Health & Management / Mammal Husbandry and Management / List of hyperlinked Techniques & Protocols:

< >  Rearing of Mammals

Bears: Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Lagomorphs: Neonatal Eastern cottontails. Click here for full page view with caption  Young domestic rabbit kits in a hay nest. Click here for full page view with caption Young pygmy rabbit kit.  Click here for full page view with caption Young pygmy rabbits with ears colour marked for identification. Click here for full page view with caption Newborn domestic rabbit. Click here for full page view with caption Doe with young kits. Click here for full page view with caption Doe with older kits. Click here for full page view with caption Hand-rearing a pygmy rabbit. Click here for full page view with caption Click image for full page view Click image for full page view Feeding leveret. Click here for full page view with caption Feeding leveret. Click here for full page view with caption Feeding leveret. Click here for full page view with caption Hand-feeding a leveret. Click here for full page view with caption Initial cage with towel nest. Click here for full page view with caption Small cage for leveret. Click here for full page view with caption Small and larger cages. Click here for full page view with caption Outdoor run for leverets. Click here for full page view with caption Outdoor run for leverets. Click here for full page view with caption Shelter for outside run. Click here for full page view with caption Leveret eating dandelion. Click here for full page view with caption Pre-release leverets in travel cage. Click here for full page view with caption Leveret release area. Click here for full page view with caption Bonobos:Orphaned bonobos need close physical contact. Click here for full page view with caption Bottle feeding an infant bonobo. Click here for full page view with caption Bottle feeding and infant bonobo through wire mesh. Click here for full page view with caption Infant bonobo holding rope. Click here for full-page view with caption Infant bonobo climbing. Click here for full-page view with caption

Introduction and General Information

Introduction and General Information

The method of rearing should be chosen with the best interest of the young animal put first. In general, parent rearing is preferable as this provides the optimum care, nutrition and introduction to species-specific behaviours and the species' social environment. However, there are situations where parent rearing is not possible, for example due to illness of, neglect by or abuse from the mother, and alternatives have to be considered.
  • In the wild, survival rates of many species are low, particularly for species which produce large numbers of offspring; in contrast, high survival rates are looked for in captive management.
  • Note: reduced success of parent rearing in captive animals may be due to inadequate provision of the correct environment, and/or lack of experience of the dam, particularly in hand-reared animals. (B438.24.w24)

(B105.19.w6, B438.24.w24, V.w5)

Bear Consideration

Bears should be parent reared whenever possible. This requires providing appropriate, secluded accommodation for females to rear their young. (B437.w36, D247.6.w6)
  • Bears have been foster-reared and hand-reared. There are potential problems with both options. 
  • Particular care must be taken if bears are to be released into the wild, to avoid hand-reared bears becoming habituated to humans and to domestic animals such as dogs.

(B285.w4, D243, D252, D253.w1, D270.X.w10, J23.4.w1, J23.9.w5, J23.16.w6, J23.22.w1, J59.12.w1, J339.20.w1, J343.49.w1, J343.52.w2, J368.11.w1) 

Lagomorph Consideration 

In general, lagomorphs should be left to raise their own offspring. Pregnant female lagomorphs should be provided with an appropriate area (nest box, burrow, area of natural vegetation) in which to build a nest and appropriate nesting material (e.g. hay, straw, natural vegetation), then left alone to rear her offspring with minimal disturbance, ensuring that the female has adequate food and water, and that the young have access to appropriate food once they start eating solids. In the event of true abandonment, young should be fostered possible, hand-reared only if absolutely necessary.
  • It is important to recognise that lagomorphs leave their young alone for most of the day, typically returning to suckle them only once in each 24 hour period (for rabbits and hares), for a short time (just a few minutes). (J82.16.w1, J40.35.w3)
  • Generally the lactation/nursing period of both rabbits and hares is quite short, 17-23 days, but the last litter of the season may be suckled for considerably longer. (J82.16.w1)
  • It is important to distinguish between typical rabbits (e.g. Oryctolagus cuniculus - European rabbit and Sylvilagus spp.) and hares (Lepus spp., including jackrabbits). Young of the typical rabbits, which raise their young in burrows or shallow excavations, are altricial, being only sparsely furred at birth, incapable of locomotion, and blind (eyes closed) to 4 - 10 days. In contrast, leverets of Lepus spp., raised above ground, are precocial: fully furred at birth, with eyes open, and able to move independently. Some species (Sylvilagus brasiliensis - Tapeti, Sylvilagus aquaticus - Swamp rabbit, Sylvilagus palustris - Marsh rabbit and Romerolagus diazi - Volcano rabbit) show an intermediate pattern, with young born better developed than the typical rabbits, but less so than the Lepus spp.. (J82.16.w1, J82.16.w2)
Ferret Consideration Ferret jills should be left undisturbed to rear their own offspring. First-time mothers are the most likely to abandon their kits, particularly if they are disturbed. (B338.26.w26)
Bonobo Consideration Bonobos have a prolonged period during which they are dependent on their mothers, carried by her and nursing to about 3-4 years of age. The parent-offspring bond is broken for female offspring in adolescence when they move to another social group, but a bond remains between moths and sons. The mother provides a high level of maternal care, although other bonobos may show some degree of alloparenting for short periods and occasionally for longer periods in unusual situations. See: Bonobo Pan paniscus - Parental Behaviour (Literature Reports)
  • Infant bonobos preferably should be reared by their mothers (B437.w24, D386.3.1.w3a), within a social group of bonobos, to maximise the ability of the slowly-maturing bonobos to assume a fully functional role within their social group. However, on some occasions it is not possible for an infant bonobo to be reared by its mother and either some form of fostering, or hand-rearing, is required. (D386.3.1.w3a)
  • There should be an institutional pre-natal management plan which considers all the options from leaving the infant with its mother, through foster-rearing to hand-rearing and re-socialisation. (D386.3.1.w3a)
  • A normal newborn great ape should "be robust with a strong grip, an animated rooting reflex, and a hearty voice which becomes apparent when the infant is distressed." The infant should be evaluated for strength and muscle tone (able to grasp tightly with hands and feet, ability to raise head), condition of the eyes (should be clear when open, and the lids should squeeze tightly together when the newborn cries), and suckling. Because much suckling by the newborn may occur at night, production of non-meconium faeces may be taken as proof of suckling. (B23.50.w50)
  • A newborn great ape infant which is not getting enough milk will get progressively weaker; this may occur over as little as 2-3 days or as long as 10 days. (B23.50.w50)
  • While up to 10% weight loss in the first week is normal in great apes, weight should then be gained every day; generally daily weight gain is lower in mother-reared than in hand-reared great ape infants. (B23.50.w50)
  • Generally, mother-rearing within the normal social group provides the best outcome for the infant great ape in social and behavioural terms. Mother-reared infants are more likely to become competent mothers. (B23.50.w50)
  • There is a range in behaviours from the competent mother great ape who cleans her infant, holds it near a nipple to encourage suckling and responds appropriately to its vocalisations, to the totally incompetent mother who may abandon or even abuse her infant. A marginally competent mother may fo example hold the infant in abnormal positions such as upside down, but with a healthy infant, she will get good positive feedback in response to correct nurturing behaviours (e.g. the infant is calmer and less fussy) which encourages correct care behaviours by the attentive dam. Note: aberrant maternal behaviour in a female which has previously been competent may indicate that the infant has a health problem. (B23.50.w50)
  • Note: vitamin D levels are low in breast milk of great apes. If the mother and infant do not have access to natural sunlight, then the infant should be provided with supplemental vitamin D. (B23.50.w50)

Published Guidelines linked in Wildpro

Return to top of page

Parent Rearing

Mammals are dependent on their mother's milk for nutrition after birth and in most mammals the mother in the main care-giver. Parent rearing is the preferred option for mammals, and if possible this should take place within an appropriate herd or family group.

There are considerable variations between species in the appropriate social groupings in which proper care of infants is most likely to occur, including:

  • Herd (many ungulates);
  • Herd but with the female temporarily absent from the herd around the time of parturition;
  • Solitary, perhaps within a nest or den (e.g. solitary carnivores);
  • Care by both parents (some primates, some carnivores);
  • Alloparenting of various degrees (e.g. some primates, elephants, some carnivores, some bats);

Every effort should be made to provide appropriate facilities and management within which parent rearing can take place. (B438.24.w24) Several factors may affect whether or not zoo animals provide appropriate parental care for their offspring. 

  • In zoos or other human-care situations, periparturient females may not be able to move away from the herd or social group, which can lead to problems of interference or infanticide either by other females or by males.
  • In monogamous species, females may not rear their young if they are separated from their mate.
  • In some species where the group (e.g. father, older offspring) assist in caring for the young, females may not be able to rear successfully if separated. 
  • First-time mothers, particularly of the more intelligent species, may not initially look after their offspring properly. Research has shown that in the wild, in a number of species the first-born infant is less likely to survive than are later offspring, once the mother is more experienced. 
  • For many intelligent, sociable species such as primates and elephants, females which have lived in a family group, and have watched their own mother or other females caring for infants, are more likely to rear their own infant successfully.
  • Note: If a mother appears not to be caring for her offspring properly, then it is necessary to make a decision: to leave the infant with her, recognising that it may not survive, but that the female may learn vital parenting skills allowing her to rear her next offspring; or to take the infant for hand-rearing or foster-rearing (see below).

Appropriate parental behaviour may be facilitated by providing an appropriate physical and social environment and by reducing stress. This includes:

  • Providing one or more nest boxes or dens.
    • Nest boxes or dens should be of the appropriate size and shape, if this is known, and placed in the preferred position within the enclosure.
    • If the optimum size, shape and placement of nest boxes or dens are not known, several of different sizes and constructions should be provided.
    • Provision of more than one nest box/den is important for some species to allow the female to sleep separate from her offspring, or to allow her to move the young from one location to another.
    • Records should be kept of nest boxes or dens used by different species and individuals, so that design can be modified and successful designs used in different enclosures/collections.
  • Providing appropriate nesting material, such as leaves, grass, straw, twigs, paper, woodwool, wood shavings etc. (depending on species).
  • Note: Instigating changes in the physical environment (e.g. provision of nest boxes, bedding) and changes in the social grouping (e.g. removal of previous offspring, separation of female and male) may be stressful; such changes should be carried out some time before parturition is expected, allowing time for the expectant mother to adjust.
  • Minimising external noise.
  • Minimising disturbance by human activity in the post-parturient period,
    • Exhibits or parts of exhibits may need to be fenced off to prevent access by the public;
    • Visits to off-exhibit areas, by staff or by others who are not known to the animals, should be minimised or totally prevented.
    • Changes in personnel working in the area should be avoided.
    • N.B. it is important to get the correct balance between monitoring the health of the neonate (and mother) and minimising disturbance.
  • Providing the appropriate social environment, considering whether or not females are normally social in the wild, and whether or not the male is normally present.
    • Females of social species may not show appropriate maternal care if separated for parturition;
    • With species which are normally found in monogamous pairs, females kept in a group may compete for infants;
    • Herd species may normally separate from the herd for parturition and, unless the enclosure allows such separation naturally, it may be necessary either to separate expectant females close to term, or to be ready to separate the female and her calf if other members of the herd start interfering.
    • In monogamous species with considerable paternal care of offspring, removing the male may lead to inadequate care by the female.
    • In species in which the male and female normally meet only for mating, it may be important to separate the male from the female.
      • "We recommend that, in the absence of compelling evidence that males are tolerant of infants, males be removed prior to parturition and reintroduced, if necessary, only when infants are large enough to be less vulnerable." (B429.42.w42)
      • Sufficient enclosure space should be available for male-female separation.
      • Depending on species, it may be necessary to remove males out of sight, sound and scent of the female.
    • Note: For many small nocturnal species, there is no data on the appropriate social environment.

(B105.19.w6, B429.4.w4, B429.42.w42, B438.7.w7)

Assisted feeding
  • A female may be caring for her offspring in an appropriate manner but appear not to be producing sufficient milk, as indicated by the offspring's weakness or poor growth. This is most common following the birth of a larger litter than usual, but can also be due to mastitis or other problems. Some females will care for the neonate but not allow it to suckle.
    • If the female does not allow suckling, check for problems such as absence of milk production, or mastitis.
  • If the female will not allow suckling, mild tranquillisation of the mother may be used (e.g. in primates) to give an opportunity for the offspring to suckle.
  • If the female is not producing enough milk, depending on the species and the temperament of the individual animals concerned, it may be possible to bottle feed one or more infants while they remain with their dam, parents, or social group, or to take one infant per day in rotation for human care and feeding.

(B105.19.w6, B429.4.w4, B492.6.w6, J83.13.w1, V.w5)

Bear Consideration

Click here for full-page view with caption

For bears to rear their cubs successfully it is necessary for the female to be provided with appropriate facilities: a concealed den in which she feels safe and undisturbed. (B10.43.w48, B214.2.3.w14, B185.37.w37, B288, B407.w9, B407.w10, D247.2.w2, D247.6.w6, B437.w36, D247.6.w6, J23.14.w1) 

Individual bears vary in temperament, including within a given species. Some individuals may successfully produce and rear cubs in situations which other female bears would find too disturbed by conspecifics in the enclosure or by members of the public outside the enclosure. The degree to which individual bears will accept close approach of their keepers while rearing cubs, and the age at which it is safe to carry out activities such as temporary separation of the mother from the cubs for cleaning the den and checking the cubs, also varies. 

European brown bears (Ursus arctos - Brown bear) are easily parent-reared in captivity; North American brown bears have also been bred and reared in zoos. (B288.w11)

  • It is recommended that the maternity den should be secluded, away from conspecifics and away from the public exhibit area. (B185.37.w37, D247.6.w6, D315.1.w1)
    • A female Helarctos malayanus - Sun bear was noted to be nervous if watched or in view of the public, indicated by her carrying her cub by its head, swinging it to and fro. (J23.14.w1)
    • Inexperienced female bears, particularly those expecting their first cubs, may be less tolerant of disturbance than are other female bears. (D247.6.w6)
  • Appropriate secluded housing is particularly important for wild-caught females, primiparous females and very restless individuals. (D247.6.w6)
  • It is preferable for a separate building to be available as a maternity area/den, including three sections/dens/cages. (D247.6.w6)
  • For Ursus maritimus - Polar bear, it is important that the den area be secluded from sight and particularly from sounds of people. (B185.37.w37)
    • The maternity area should be secluded from the male and from other animals. The male's scent may discourage the female from using the den, or increase her stress. (D315.1.w1)
    • Often, a small maternity den and a larger adjacent area are made available to the female. (D315.1.w1)
    • Signs of stress may include pacing, head swaying, aggression towards keepers, abandonment of the cubs or even cannibalism of the cubs. (D315.1.w1)
  • The size difference between males and females can be utilised: a door of a size allowing the female but not the male to enter can be used to ensure only the female can access the cubbing den area. (B407.w5)
  • Within one of the indoor areas should be a cubbing box or kennel to serve as a maternity den. (B407.w8, D247.6.w6)
    • The cubbing box should be relatively small.
    • Small openings high up are recommended to improve ventilation without producing draughts.
    • Nesting material should be provided, such as straw, wood chips, bark or dry leaves.
      • Avoid long straw due to the potential risk of strangulation of a cub.
      • Ensure that the nesting material is clean and that it is low in dust.
    • A video link with sound recording should be installed if possible; if not then a microphone should be installed so that the cub's vocalisations can be monitored.
      • A baby monitor can be used for monitoring using sound. (B407.w9)
    (B407.w8, B407.w9, D247.6.w6, D315.1.w1)
  • One of the neighbouring cages should be fitted out as a cub playground, with thick straw on the ground for safety when first climbing, ropes, tree trunks (firmly secured), barrels and plastic tubs held together to form climbing frames and resting places. (D247.6.w6)
  • Preferably there should also be an outdoor area for the female and cubs to use, separate from any other bears in the main enclosure, so that both the female and her cubs, and other bears, can have outdoor access. (D247.6.w6, B407.w5, B407.w6, B407.w8)
    • Any pool should have shallow sides or an escape ladder which cubs can use. The water level should be low when cubs are very young, or the pool may even be drained and the bottom filled with straw. (B407.w8, B407.w9)
Management of the female
  • The females should be separated from the male and confined in the maternity area for some time before the expected parturition date, so that she becomes used to the cages and the situation. (D247.6.w6)
    • For Ursus maritimus - Polar bear it is recommended that the female should be given access to the cubbing den routinely before she is separated into this area. (D315.1.w1)
    • In Tremarctos ornatus - Spectacled bears, separation one to two months before the expected cubbing date is suggested. (P77.1.w17) Alternatively, separate the female from the male when she starts to avoid him all the time. (B407.w8)
    • For Helarctos malayanus - Sun bear, it may be difficult to determine the correct time for separation; observation of the female's behaviour should be used, separating the female when her behaviour (nest building etc.) indicates parturition will occur soon. (B407.w9)
    • Some individual bears will rear their cubs in situations where they are separated from the male only very shortly before parturition, or even after parturition has occurred. (B407.w5, B407.w6)
  • Disturbance by both other animals and unfamiliar people must be avoided, (B407.w8, B407.w9, D247.6.w6) particularly in the early period after parturition, e.g. the first month. (B407.w8).
  • Only a familiar keeper or keepers should be allowed near the maternity area. (D247.6.w6)
  • Necessary management should be carried out quietly, with effort to reduce noise, and on a regular schedule, so that the activities are predictable. (D247.6.w6)
  • Do not clean the den out in the first weeks after parturition; cleaning activities may disturb the female sufficiently that she kills her cubs. (B407.w6)
  • A system was set up at Denver Zoological Gardens allowing the Ursus maritimus - Polar bear to be separated from her cubs periodically so that the den could be cleaned; this started no earlier than four weeks after the cubs were born - later than this in the first years (initially at 12 weeks). (J23.39.w1)
  • At one facility, increased rearing success was achieved by allowing the female Ursus maritimus - Polar bear choices of dens, which let her move the cubs if she wants to, and by allowing her to choose her routine. (D315.1.w1)
Food and water
  • Water should always be available to the female bear while in the maternity area. This may be provided by an automatic drinking device (preferable to ensure water is always available without disturbance) (B407.w8a, D247.6.w6) or by a water bowl fixed to the bear's side of the door and filled from the outside using a hose, with care not to disturb the bear.
  • It has been suggested that food should be withheld from female bears once they are moved to cubbing dens when the cold weather arrives, to break the habit of the bear leaving the den at the usual feeding time. (B288.w11)
  • Bears may not eat for a few days before parturition and for a few weeks after parturition. (D247.6.w6)
  • It may be best not to offer food for the first three weeks after parturition, to minimise the risk of disturbing the female and breaking the bond with her cub(s). (D247.6.w6)
  • If food is provided, it should be placed in an adjacent area to which the female has access, not inside the cubbing den itself. (B407.w6)
  • Food could be provided via a chute, to minimise keeper approach near the den in the early stages after parturition. (B407.w8a)
  • Initially provide small amounts of food, increasing quantities as the female's appetite increases. (B407.w9)
  • The bear should be monitored closely to enable prediction of the cubbing date and to ensure that any problems are identified quickly and intervention is carried out if necessary. (D247.6.w6)
  • Preferably, observation is carried out by video/microphone monitoring of the cubbing box. As an alterative, a keeper familiar to the bear may approach quietly and listen/observe through a peephole. (D247.6.w6)
  • If video is used, a series of squares of known size (e.g. 2 cm or 3 cm) painted on a wall may be used for improved accuracy in estimating the size of cubs. (B407.w8a)
  • Vocalisations are important in monitoring:
    • The sound of cub vocalisations is the best indicator that birth has occurred. (D247.6.w6)
    • Lip smacking of the cub while drinking is a positive indicator. (D247.6.w6)
    • "Humming" of the cub while lying with a teat, its own paw, or its mother's hair in its mouth is also a positive indicator. (D247.6.w6)
    • Prolonged squeaking indicates a problem. Squeaks from the cub should elicit maternal care, therefore occasional brief squeaks are normal but prolonged squeaking is not. (D247.6.w6)
  • Behaviours of the female indicating a problem include:
    • Lack of response to squeaking of the cub(s); (D247.6.w6)
    • Leaving the cubbing box in the first few days after parturition. (D247.6.w6)
  • Visual indications of a problem include: 
    • Cubs lying in a corner of the cubbing box, not being cared for; (D247.6.w6)
    • Injuries to the cubs, indicating maternal aggression. (D247.6.w6)
  • Handling of cubs should be avoided if at all possible. (D247.6.w6)
    • Weighing and measuring of cubs should be carried out ONLY if this is not likely to disturb the mother and have a deleterious effect on her relationship with her cubs. (D247.6.w6)
    • Inflammation of the navel, which may occur due to excessive licking, or due to infection, should be treated only if absolutely necessary. (D247.6.w6)
    • Tolerance of human presence will depend on the bear's character and on her pre-parturition relationship with her keeper. (D247.6.w6)
    • A system was set up at Denver Zoological Gardens allowing the mother to be separated from her cubs periodically (at two-week intervals, starting when the cubs were at least four weeks old) so that the den could be cleaned; cubs were examined and weighed during these separations. There were no problems with maternal rejection or aggression due to these procedures. (J23.39.w1)
Females and larger cubs
  • In general, females and cubs which have left the den need an enclosure similar to that for adult bears. (D247.6.w6)
  • Some modifications may be needed to make the enclosure safer and more negotiable for cubs: (D247.6.w6)
    • Adding temporary extra treads to steps to reduce their height;
    • Pool modifications: draining the pool and filling it with straw, or lowering the water level, and providing a ladder if the pool sides are relatively steep. (B407.w8, B407.w9)
  • Females and their cubs should be kept together for 1.5 to 2.5 years, as is normal in the wild. (D247.6.w6)
  • It may be possible to reintroduce the female and cubs to the male, but this depends on the temperament of the female (whether she will defend her cubs) and the male (how aggressive he is). (D247.6.w6)
  • For Tremarctos ornatus - Spectacled bears, it has been suggested that the cubs should be removed from their mother when they are 12-18 months old, since the female will come into oestrus when they are about 18 months old and social problems may occur at this time if the cubs are still present. They should certainly be removed before they are 22 months old, to avoid problems around the time of parturition (e.g. the mother may become agitated when her offspring are removed, and then not settle in time to look after the new cubs). (B407.w8)
Reintroduction of female and cubs to other bears
  • If the female and cubs are to be reintroduced to the male, this must be carried out gradually and with care. (D247.6.w6)
  • In Helarctos malayanus - Sun bear, females with cubs have been successfully reintroduced to the male in several collections. (D247.4.w4)
    • Re-introduction has been carried out with the cubs at two to nine months of age. (D247.4.w4)
      • In one case, the bears were able to contact one another through the bars from 92 days, and were together from 120 days. (B407.w9)
    • Bears in such groups may be seen in close proximity to one another. (D247.4.w4)
    • Males as old as 15 to 19 years of age have been seen playing with their cubs. (D247.4.w4)
  • Reintroduction of female and cubs to the male has not been reported for Melursus ursinus - Sloth bear. (D247.4.w4)
  • In five of eleven collections breeding Tremarctos ornatus - Spectacled bear in Europe, reintroduction has been successful; one of these collections stopped the practice after acquiring a new, more aggressive male. (D247.4.w4)
    • Reintroductions took place when the cubs were four to nine months old. (D247.4.w4)
    • Males reacted variously with chasing of cubs, tolerance, or positive interest and even playing. (D247.4.w4)
  • In other bear species (Ursus arctos - Brown bear, Ursus americanus - American black bear, Ursus thibetanus - Asiatic black bear and Ursus maritimus - Polar bear), reintroductions of female plus cubs-of-the-year to a male in the same enclosure have been carried out with varying success. (D247.4.w4)
    • Reintegration is most likely to be successful if: (D247.4.w4)
      • The male is unaggressive;
      • The female is sufficiently defensive of her cubs;
      • The cubs are able to overcome their fear of the male. 


    • Note: In Ursus maritimus - Polar bear, success one year does not necessarily mean success in another year. (D247.4.w4)

Examples of successful parent-rearing of difficult species

For Melursus ursinus - Sloth bear, observations at Amsterdam zoo suggest that females prefer small dens (e.g. 145 cm x 70 cm), kept dark, for cubbing. Two females cubbed together in a single dark den 170 x 140 cm. Straw bedding was provided but not used. The dens had heated floors and heated air currents which provided ventilation and maintained a temperature of 15 - 20 C. Bears which reared their cubs successfully did drink but did not eat for about one to 2.5 months after cubbing. (B437.w36) 

Tremarctos ornatus - Spectacled bears have successfully reared cubs in the following conditions. In most cases the female was separated from the male some time before the expected birth date, provided with a secluded den containing a wooden cubbing box (or in one case ample bedding), and disturbance was also minimised. One female was left on exhibit with a hollow log or a wooden crate as a cubbing box, with other bears removed. It was noted that the females often did not eat in the first several days after parturition, although most did drink during this time. 

Signs which may indicate pregnancy include a gradual decrease in appetite, increased aggression towards/decreased tolerance of the male, reduced activity, nest building in the den and vulval swelling. (P77.1.w18)

  • Example 1: (J23.19.w3)
    • The male was removed from the exhibit about two months before the expected parturition date and visitors were restricted. 
    • The indoor den was 2.7 m by 2.3 m, and 2.1 m high, warmed by radiant heating and with a wooden cubbing box, raised off the floor, measuring 2.34 x 1.07 m and 0.91 m high. The box had a lip 15 cm high, preventing bedding from spilling out.
    • Following parturition, the female was locked into her den; water was available.
    • All noise-producing activity near the den was avoided.
    • For the first month, human contact was limited to a single, familiar, keeper.
    • The keeper first entered the enclosure on day three, filling the water bowl (which was dry).
    • Food was offered for the first time five days after parturition.


  • Example 2: (J23.21.w1)
    • The male was separated totally from the female in November.
    • The den was isolated.
    • Plenty of straw was provided as nesting material.
    • It was noted that a secure rearing area is required.


  • Example 3: (J23.17.w3)
    • The male and female were separated from early October (after displaying aggression to one another).
    • The female was given access to a windowless maternity den, 3.7 x 3.0 x 3.7 m, containing a wooden cubbing box 1.12 x 0.96 x 1.0 m high, with an entrance 0.43 x 0.66 m high. She also had access to the adjacent den (of the same size) which had large windows.
    • During pregnancy the female was disturbed as little as possible, with care taken not to deviate from the normal routine in cleaning and feeding
    • Extra woodwool bedding was provided 23rd January and the female took this into the den; the cubs were born 24th January.
    • After parturition, cleaning was stopped, there were no intrusions near the den and food was offered by being slid under the sliding door.
    • The female did not eat on the day of birth and did not leave the maternity den at all for the first 11 days (she did drink; water was available at all times); she ate half a loaf of brown bread at 11 days then nothing else for another nine days. She started eating brown bread on a regular basis from 25 days after cubbing.
    • The female was not given access to the outdoors until the cubs were six weeks old; she did not emerge for a further four days and then only briefly to eat some grass; she then gradually became less withdrawn.


  • Example 4: The female was separated from the male 1.5 - 2 months before parturition, into a cage containing a wooden nest box of 2.0 x 1.5 x 1.5 m. It was noted that the female did not leave her cubs alone at all in the first one to 1.5 weeks after they are born, and carried them with her in her teeth if she left the house. Also, generally she did not eat or drink for the first four or five days after parturition. The female suckled her cubs while sitting with her back against the wall. (P74.1989.w1)
  • Example 5: The den area was not suitable for cubbing. The female chose a large hollow log within the exhibit for cubbing. She was left on exhibit, without the other bears, until the cubs were six months old, at which time they were gradually reintroduced to first an elderly female then the male. A second litter was reared in a small crate which had been placed in the dry moat for this purpose; the female used pine needles and oat hay provided as bedding in the crate. (P77.1.w8)
  • Example 6: the female is separated into the maternity den at about 150 days after mating, wood shavings are provided for bedding and disturbance is minimised, with cleaning and feeding at the same time each day. The keeper listens each morning; if sounds of a cub are heard, cleaning stops for two weeks but food is offered daily. (P77.1.w11)
  • Example 7: the female was separated into a secluded indoor cage containing a wooden cubbing box one metre square with an entrance 75 cm by 50 cm. The den had sawdust on the floor and straw bedding was provided in the box. (P77.1.w15)

Helarctos malayanus - Sun bears

  • At Tama Zoo, Tokyo, Japan, important factors in successful rearing were thought to include: (N18.48.w2)
    • Partial not total blockage of den windows, to reduce humidity and improve air circulation; a fan was sometimes used to increase air flow.
    • Free access to the outside enclosure from ten days onward during the day and from about 10 weeks day and night.
      • Hair loss and a skin rash cleared up once full outside access was provided. 
    • Slender, sun-dried bamboo stalks rather than straw given as bedding.
    • Minimum disturbance: keepers avoided going near the den in the days after the birth. 


  • At Cologne Zoo, the female was separated from the male when her behaviour (e.g. nest building) indicated imminent parturition. She was provided with a maternity area consisting of three cages. One cage contained the cubbing box (90 x 200 x 100 cm), and the box and cage contained straw. Water was provided at all times. Observation was carried out using an acoustic baby alarm, and visually through a small opening in the keepers' passage to see e.g. if food was eaten. Once parturition occurred, the bear was left undisturbed for three days, then from day four a known keeper provided food (small amounts initially), always at the same time each day. Cleaning was carried out based on the bear's behaviour and the degree of soiling. Cubs were wormed and sexed at about 70 days, allowed outside at about 92 days, and no longer separated from the male by 120 days. (B407.w9)

Ursus maritimus - Polar bear 

  • At Brookfield Zoo, Illinois, maternity caves were constructed within existing dens. Made from cement construction blocks smoothed off with a cement layer, each was a "hemi igloo", with a 1.8 m long, 60 cm diameter tunnel leading to a semi-circular chamber about 1.5 x 2.4 m and 1.2 m high. A 20 cm high lip between the tunnel and chamber helped to retain bedding. Embedded heating pads were included in the cement floor and the floor sloped to a drainage hole to make cleaning easier. Lighting in the dens was kept very dim. (J23.14.w2)
    • The females, one to each den, were confined from an unspecified date in October, after which they were not fed (appetites had anyway reduced) but water was always available. The keeper visited the den areas only two to three times a week. Cubs were born 17th and 26th November and 11th December. One female, who was in relatively poor body condition, did not rear successfully. The other two females were very secretive after parturition. They first ate a month after cubbing; the cubs were only seen after two months. At 3.5 months they were allowed out into outside areas with their mothers. (J23.14.w2)
  • At Tulsa Zoo, a cubbing den, unheated (outside temperature reached down to -17 C), was built from two cylindrical cement pipes, each 2.4 m long and 1.2 m diameter, buried in an earth mound. A ventilation pipe led out of the back of the pipes. An enclosed ramp led up from the pipe to a 2.4 m den. The cubbing den was observable using CCTV. Wood shavings were provided, 30 cm deep, as bedding. (J23.17.w4)
    • The female was fed extra food "to repletion" for four months, then feeding was stopped on 14th October and on 26th October the female was confined to the cubbing den; water was provided in a bowl just inside the door, filled by a hose. For two days she was restless and pawed at the door, then settled. In early November she moved bedding, appearing to prepare for cubbing. She then slept most of the time until cubbing on 24th November. The female was only allowed out of the cubbing den when the cubs were 72 days old; they were given access to the main indoor area and pool when the cubs were 111 days old, and access to the outside when they were 125 days old. The female was not fed for nearly four months from first isolation (first fed when the cubs were 73 days old), but water was always available. (J23.17.w4)
  • At Denver Zoological Gardens, pregnant females were provided with a maternity den which contained straw for bedding. This was connected to a corridor and a further holding area where food and water were provided. A 45 cm tall barrier kept the cubs in the den but permitted the female to leave it. Video (infrared camera with 24-hour videotaping) and audio surveillance were arranged for monitoring the female and cubs. Because females fed while in the den, and defecated and urinated in the den, a system of regular cleaning was instituted, starting as early as when the cubs were four weeks old, and repeated at intervals of two weeks. The mother was separated from the cubs while cleaning was carried out, and the cubs were also examined at these times (e.g. weights recorded). There were no problems with maternal rejection or aggression due to these procedures. (J23.39.w1)

Lagomorph Consideration 

NOTE: It is important to recognise that lagomorphs leave their young alone for most of the day, with rabbits and hares typically returning to suckle them only once (sometimes more often) in each 24 hour period, for a short time (just a few minutes). The fact that the female does not remain with her offspring does not mean she has abandoned them. Pikas suckle their young more frequently (e.g. every two hours) but also remain apart from their offspring most of the time
Domestic rabbit
  • A breeding rabbit doe should be provided with a large hutch which will give enough room for her and the developing kits. (B616.7.w7)
  • Provide a nest box. The sides of the box should be high enough to keep the kits in, but low enough to allow the doe to access it easily. (B616.7.w7)
  • The whole box can be enclosed except for the top half of one side. (B550.16.w16)
  • Provide nesting material such as soft meadow hay, finely shredded paper or dried moss. (B616.7.w7)
    • Nesting material should be provided a few days before the expected parturition date. (B550.16.w16)
  • Make sure the doe can get away from the kits properly. (D360)
    • In the wild, the does would visit her kits once a day to feed them and otherwise be absent, as an anti-predator strategy. It may be stressful for the doe if she cannot get out of visual and olfactory contact with the young for most of the time. (D360)
  • Clean and disinfect the nest box before the expected date for the doe to litter, in order to minimise bacterial contamination. (B606.6.w6)
  • Remove the buck if you thought you had two females and have now discovered you had one female and one male. (B616.7.w7)
    • The male will need to be castrated [Castration of Rabbits] and kept separate from the female for at least four weeks and preferable six weeks as the buck may remain fertile for at least four weeks after castration and sometimes longer than this. (B600.3.w3, B601.1.w1 P113.2005.w6)
    • Even if breeding is wanted, it is advisable to remove the buck while the female is in late pregnancy, since otherwise he will mate her soon after parturition and she will be pregnant again immediately. (B600.3.w3)
  • Note: if female rabbits are housed together and one has kits, there is a risk of other does cannibalising the kits, therefore they should be removed. (B600.3.w3)
  • Make sure the doe and kits are protected from environmental extremes and from the stress of predators. (B606.6.w6)
    • A frightened doe may accidentally crush her litter, or scatter her kits (and will not retrieve them). (B606.6.w6)
    • Sudden changes in environment act as stressors for both doe and kits; this can predispose to development of disease. (B606.6.w6)
  • Avoid disturbing the nest; a single inspection may be carried out by carefully parting the nesting material over the kits 24 hours after they are born; after that, the nest should be left undisturbed for five days or more. (B616.7.w7)
    • Leave the kits alone: in the wild, vibration and disturbance indicates the arrival of the doe to nurse them; it may be stressful for the kits to prepare to nurse then have the doe not appear. (D360)
    • Daily checks has been suggested. (B606.6.w6)
      • The kits should have rounded abdomens and smooth skin if they are being fed. If the kits look hunched up and dehydrated this suggests they have not been fed. (B606.6.w6)
      • Any soiled bedding or dead kits should be removed. (B606.6.w6)
    • Note: a female producing a lot of milk may overfeed them, particularly if she only has a few kits. Excess milk can lead to bacterial overgrowth in the caecum and resultant enterotoxaemia. (B606.6.w6)
  • If you need to handle the kits [e.g. to return a kit to the nest], rub your hands on the doe first to ensure you place her scent on them not your own. (B616.7.w7)
  • If the doe makes two nests and produces some kits into each nest at parturition, the nest material should be rearranged to make one nest holding all the young. (B550.16.w16)
  • If a doe has her litter on the floor or the hutch rather than in the nest box (this is most likely with first-time breeders), the kits can be picked up and placed in the nest. (B616.7.w7)
    • Any kits found outside the nest should be returned to it; the doe will not do this. (B606.6.w6, W730.Dec08.w1)
  • If the kits are cold, put them in a box in a warm place. (B616.7.w7)
Inducing parturition
  • Oxytocin should be used to induce parturition if pregnancy continues to 34 days, since kits retained in the uterus past 35 days will die. (B550.16.w16)
    • Sometimes, parturition is divided with some young being born several hours after the others, and occasionally days apart. If young are born three days apart or longer, the additional kits will not survive. (B550.16.w16)
    • The presence of additional kits still in the doe can be determined by palpation of the doe's abdomen one day after parturition. If any kits have been retained, delivery may be induced using oxytocin. (B550.16.w16)
Cannibalism and desertion
  • Some females do not stop after eating the placenta and cutting the umbilical cord, but may continue to eat parts of the young. This may be due to insecurity as well as being seen associated with poor nutrition, and sometimes having a hereditary component. (B550.16.w16, B625.4.w4)
  • Cannibalism and desertion are more likely to occur with primiparous, stressed or overcrowded does. (J29.10.w2)
  • Note: does will not return their young to the nest box. Any kits found outside the nest should be returned to it. (B606.6.w6, W730.Dec08.w1)


  • Note that sometimes lactation does not start for as long as 24 hours after parturition. (B606.6.w6, B616.7.w7)
    • If kits have not been fed for 48 hours, supplementary feeding is required. (B606.6.w6)
    • Note: Some does do not have well-developed mothering instincts. (B606.6.w6)
  • If you have a tame doe, used to being handled, and she appears reluctant to feed the kits, take the whole family to a warm place, lie the doe on your lap belly upwards and try placing the kits where they can latch onto the teats; this may aid milk flow. (B616.7.w7)
    • Or try holding the doe steady and placing one or two kits under her. (W730.Dec08.w1)
Feeding the doe and kits
  • Provide adequate food for the doe: 
    • The doe may eat twice as much during late gestation as when she is not pregnant, and three times as much during lactation. (B336.42.w42)
    • The energy demand on the doe will increase to x 3.5 maintenance at peak lactation. Increase the food gradually, starting from five to seven days after parturition, early overfeeding may lead to obesity or mastitis if there is excessive milk production. (B541.16.w16).
    • Consumption of both water and caecotrophs increases ten-fold during lactation. (B612.8.w8)
  • Provide food for the kits from about 16 days, also ensure water is available. (B616.7.w7)
  • Note: rabbits show increased susceptibility to the development of enteritis during the weaning period. Use of probiotics at this time may reduce the development of enteritis. (B614.14.w14)

Handling the kits 

  • Domestic rabbit kits should be handled regularly and frequently once they start moving around, to improve their tameness and make them better pets. (B338.1.w1, B622.3.w3)
  • Kits which have had regular contact with humans in the period one to six weeks of age are generally well socialised to humans, considering handling by humans to be normal, while rabbits which have not been handled during that early socialisation period are more likely to be nervous or aggressive. (J15.27.w2)
    • Experimentally, brief (a few seconds, touching each kit to check they were still alive), carried out in the first half hour after the kits nursed, was found to be sufficient to reduce fear responses to humans. (J288.95.w1)

Separating the doe and kits: 

  • Leave the doe and kits together for about 6 - 8 weeks. (B616.7.w7)
  • When removing the doe, initially she may be placed in a hutch next to the one the kits are in. (B616.7.w7)
Wild lagomorphs
Provide an appropriate environment, choice of nest boxes/nesting areas, and appropriate nesting materials. (V.w5, V.w123)
  • A female Romerolagus diazi - Volcano rabbit gave birth in her nest box not long after arriving at Jersey Zoo and was first seen sitting over the kits, having cleaned them. Later, the kits were seen covered in hay while their mother sat by them. With a second litter later in the year, she had constructed a fur-lined nest. (J23.10.w4)
  • Female Romerolagus diazi - Volcano rabbits at Chapultec Zoo, Mexico City gave birth in a fur-lined nest constructed in bundle-grass (zacaton) vegetation. When no such zacaton was available (before it had grown up properly in the enclosure), one female nested in an indoor den. (J23.26.w2)
  • Cottontail rabbits (Sylvilagus sp.) in captivity, provided with straw, made a cavity in the straw, lined this with fur, and pulled straw over the nest so it was not visible. (J332.10.w1)
    • Rabbits without suitable nesting material failed to rear their young. (J332.10.w1)
    • When the young approach weaning age, small refuges, each large enough for one juvenile to enter and hide in, should be provided, in case the female starts to resent the young. (J332.10.w1)
  • For Brachylagus idahoensis - Pygmy rabbit, provision of soil (0.5 - 1.0 m deep) in which the female can dig her natal burrow appears to be essential for successful rearing of young. Females kept on rubber substrate with nest boxes and hay for nesting failed to rear their young for more than 4 - 5 days. (J332.87.w1, V.w134)
    • A very few females have given birth in plastic nest boxes with hay bedding. (V.w134)
    • A probiotic is given, 0.3 - 0.4 mL daily on greens to pregnant and lactating females, 0.1 mL orally per kit for the first two weeks after emergence from the burrow and additionally if they become ill, to boost beneficial gut microorganisms. (V.w134)
  • Sylvilagus bachmani - Brush rabbit were bred successfully by simply placing them in large pens (larger than the typical home range (0.33 ha) for the species) with adequate natural vegetation for food and cover. (B623.w1)
  • At Denver Zoological Gardens, a female pika (Ochotona princeps - American pika) gave birth on hay in an underground nest box. She soon covered the young with hay. (J23.15.w6)
  • At Denver Zoological Gardens, a female pika (Ochotona princeps - American pika) reared young in an enclosure with a male and another female. Left alone, she spent her days grazing. The male never approached the nest. The babies, black and furless with closed eyes at birth, were seen at one week of age when they started exploring the den around the nest; by this time the eyes were open and they were covered with light grey hair. By two weeks they were one third the size of an adult, with a more rounded appearance, and were making short explorations into the outside area. In the third week they were moved to a new nest in a talus mound, and explored more. By the fourth week they were weaned and independent. (J23.15.w6)
Returning free-living lagomorphs to the nest

It is unlikely that young of free-living rabbits which use burrows (e.g. Oryctolagus cuniculus - European rabbit ) will be presented for rearing unless they have been brought in by a domestic predator (cat or dog). This scenario is however not uncommon with respect to lagomorphs such as Sylvilagus spp. which make a nest at ground level . Well-meaning but uninformed people may remove the young, thinking they are abandoned(B602.13.w13, N35.8.w1). Assuming the nest location is known, it may be possible to return the kits. (N35.8.w1)

  • The likelihood of the young being accepted by the female if they are returned to the nest may be affected by how long they have been absent.
    • If the young have been removed from the nest for only a few hours, during daytime, the mother is very likely to return.
    • If they have been removed for a longer period, and particularly overnight, the female will have checked the nest and found it empty, possibly more than once. It is not known how long she will continue checking the nest before abandoning the nest site.
    • If it is more than 36 hours since they were removed, the mother is unlikely to return.
  • Wear gloves at all times when handling the young.
  • The young should be stimulated to urinate and should be well hydrated before being returned to the nest site.
  • Locate the original nest site and replace or repair the nest (wear gloves to minimise transfer of human scent).
  • Place the young back in the nest and cover them with the original nest material; leave the nest looking as natural as possible.
    • If they have closed eyes, they can be returned any time during the day; if their eyes are open, return them just before dusk so it is less likely they will move away.
  • Leave the area quickly to avoid drawing the attention of predators to the site.
  • If you are concerned the mother may be dead or have abandoned the site:
    • Place two or three smooth, lightweight sticks on the top of the nest forming a geometric pattern (e.g. a cross), so that observation at a distance can determine whether the top of the nest has been disturbed.
      • Avoid use of rough sticks which may stick in position on the nest material.
    • If still unsure then wearing gloves carefully lift the top off the nest. If the mother has returned the young will be warm, plump and resting; there may be new fur in the nest also.
  • If the exact location is not known, it may still be worthwhile trying to return the young if their eyes are open.
    • Return the young at dusk, leaving them approximately where they were found; they may find the nest or their mother may find them.
  • Returning the young to the nest is NOT appropriate if:
    • The nest was disturbed by cat predation;
    • The nest was disturbed by a dog and it is not possible to ensure it will not be disturbed again;
    • The young have been out of the nest for more than 36 hours;
    • The young are severely dehydrated;
    • The young have been injured by a cat, or have more than very minor injures from e.g. a mower.
    • The location of the nest is known to cats or dogs who may be able to access the site.


Ferret Consideration The pregnant jill should usually be separated both from the male and from other ferrets a while before the expected parturition date.
  • Separate the jill (B631.17.w17) about 7-10 days before parturition. (, B651.6.w6)
  • About 10 days before parturition the mammary glands swell, the nipples enlarge and the female starts making a nest. (B651.6.w6)
    • There may be a little discharge from the nipples shortly before the birth. (B652.7.w7)
    • Mammary glands swell about a week before birth; it may be possible to express milk only once the kits are born. (B627.8.w8)
  • Some jills are tolerant of other jills and can be left in the enclosure with them, but others must be separated. (B651.6.w6, B652.7.w7)
  • If the jill is being moved from her usual accommodation, move her at least two weeks before the expected parturition date, so the new area is familiar by the time she gives birth. (B652.7.w7)
    • If she has been housed with the male during pregnancy, remove the male once the jill starts nest building. (B652.7.w7)
  • Note: The cage must not have any openings larger than 2.5 x 2.5 cm (1 x 1 inch) or kits near to weaning may be able to get out. (B627.8.w8)

Nest box and bedding

  • Provide an enclosed nest box with a small pophole entrance high enough up to stop the kits falling out. Give at least eight inches of straw bedding or four inches of wood shavings. (B652.7.w7)
    • Kits may get tangled in paper. (B652.7.w7)
    • Hay is too warm. (B652.7.w7)
    • A small nest box, about 12 x 6 x 6 inches 930 x 15 x 15 cm) is recommended. (J495.21.w5)
    • Note: the female also uses her own fur to make a nest. (J495.21.w5)
  • Before the expected parturition date, provide an insulated box with bedding such as shredded paper, hay or towelling. (B631.17.w17)
  • The nest box must not have any sharp edges, and the exit from the box to the cage, for the jill, must be smooth to avoid abrading her nipples and mammary glands. (B627.8.w8)
  • Note: Keep the temperature close to constant, avoiding a wide diurnal temperature variation which may result in abnormal behaviour of the jill and rejection of the kits. (B627.8.w8)
  • Dystocia is rare. (B631.17.w17, B652.7.w7) Can be common. (B627.8.w8) See Dystocia in Hedgehogs, Lagomorphs and Ferrets
  • Usually, all the kits are born within a few minutes of each other (B652.7.w7), but sometimes It may take several hours for the full litter to be produced. (B631.17.w17, B652.7.w7)
    • Commonly, delivery of the whole litter occurs within 2 - 3 hours; sometimes it takes longer. (B627.8.w8)
    • If delivery is prolonged, keep the kits warm and place them back with the jill once the last kit is born and she can care for them. (B627.8.w8)
  • It is common for the jill to produce dark tarry faeces after giving birth and eating the placentae. (B631.17.w17, B652.7.w7)
  • Note: an inexperienced jill may produce her kits in the latrine area rather than the nest, and may eat her young.  (B652.7.w7)
  • If it is very warm, the umbilical cords can become dried and entangled before the jill eats these. (B652.7.w7) See: Umbilical Cord Entangelment in Ferrets
  • If the jill fails to settle and care for the kits after parturition, give her a warm, palatable meal. (B627.8.w8)


  • Avoid disturbance when the litter is young. (B627.8.w8, B652.7.w7)
    • Avoid e.g. unusual noise near the jill and her kits, and keep unfamiliar people away, particularly in the first five days. (B338.26.w26)
    • If disturbed, the female may kill and eat her kits. (B651.6.w6)
    • Leave the nest untouched (i.e. do not replace the bedding at all) from the time the female starts building her nest until the kits have left the nest. (B652.7.w7)
  • Ensure the jill has an adequate nest, the correct environmental temperature, adequate access to food and water, and is protected from disturbance. (B627.8.w8)
  • A female who fails to look after her kits but does not harm them may be placed with the litter in a very small solid-bottomed cage with just enough room for a contained of bedding able to hold her and the kits, and a litter pan, with a water bottle attached to the outside, and small amounts of food offered frequently. Some jills then accept the litter. (B338.26.w26)
    • Once the jill is looking after the litter, it may be possible to give her more room, although some inexperienced jills then leave the kits for too long. (B338.26.w26)
  • If the jill does not settle and the kits do not have a chance to suckle, the lack of nursing stimulus means that the jill's milk production stops. (B338.26.w26) See: Lactation Failure and Nursing Sickness in Ferrets
  • Leave the jill and litter together (and usually away from other ferrets) for about 6-8 weeks, until they are weaned. (B652.7.w7)
  • If several females are housed communally, ensure each pregnant female can choose her preferred nest box. (B652.7.w7)
    • Some females are happy to let another female assist as an "aunty" in the later stages of rearing. (B652.7.w7)
  • Increase the amount of food provided as the jill's appetite increases; make sure it is high in protein, not carbohydrate. (B652.7.w7) See: Food and Feeding for Mammals
  • Note: the jill may look very thin as she loses her winter coat during the pregnancy. (B652.7.w7)
Feeding the jill
  • Ensure that food and water are placed so that the jill can eat and drink easily without leaving the nest. If the jill does not have access to enough food and water she cannot produce enough milk. (B338.26.w26, B627.8.w8)
  • Provide a very good quality diet, high in protein (at least 34-36% protein) and high in fat (at least 20% fat). (B338.26.w26)
  • Dry diets can be supplemented with foods such as HIll's AD or Nutrical (Tomlyn Co.). (B338.26.w26)
  • Make sure pregnant, and particularly nursing, jills always have ample water available. (B338.26.w26, B652.7.w7)
    • Check any water bottle is working properly and actually providing water to the jill. (B652.7.w7)
  • Even with good feeding (35 - 40% protein and 10 - 20% fat) the jill will become thin during lactation. (B627.8.w8)

Kit development and feeding

  • If the kits are well fed and healthy, they will lie close to the jill, quietly, either nursing or sleeping for the first weeks. By three weeks of age they start to explore. (B338.26.w26)
  • From about three weeks old, kits will start nibbling soft food. Good quality kibble moistened with water is appropriate. (B338.26.w26)
  • Soften the jill's diet with water, and add animal fat to make it 30% fat. Provide this once or twice a day, removing it once the ferrets stop eating (or it will be walked through and may be soiled with faeces). (B627.8.w8)
  • By six to eight weeks, the kits will be weaned. (B338.26.w26)
  • If supplementary feeding is needed due to reduction in the jill's milk production (e.g. with illness), use a kitten or puppy milk replacer with cream added to bring the fat content up to 20%: for example Esbilac (PetAg) mixed 3:1 with whipping cream. (B338.26.w26)
    • Supplement at least six times a day; with feeding the kits become stronger, better able to nurse, and the nursing stimulus encourages lactation. (B627.8.w8)
    • For further information on feeding kits see Hand-Rearing Ferrets
  • Milk produced by the jill has a 8 - 10% fat content at parturition; by three weeks this has increased to 15 - 20%. (B627.8.w8)

Illness in the jill

  • A jill with an acute infection or other systemic disease will stop milk production. Kits will cry and move around rather than being either nursing or lying quietly next to the jill; they will also look thin. (B338.26.w26) Diseases to consider include:
  • Very young kits may simply be lethargic if unfed, while older kits are more likely to squeal sharply. (B652.7.w7)
    • Initially they cheep constantly; later, as they get chilled, they stop trying to nurse. (B627.8.w8)
  • If illness occurs very early in the rearing period, the jill's milk production may stop entirely and not restart. however, later in lactation, milk production may resume if the illness is treated and the kits have been left with the jill to provide a suckling stimulus.
    • Feed the kits at least four times a day, but leave them with the jill.
    • Encourage the jill to feed on high-calorie treat foods such as Ensure Plus (Ross), Nutrical, or Hill's AD while she is ill. (B338.26.w26)
Handling the kits
  • Handling of ferret kits should begin once they are wandering around the cage, with their eyes open. (B631.17.w17, B651.4.w4, B652.7.w7)
  • Initially simply stroke the kits gently while talking in a soft, soothing voice. Do this for a couple of days. (B651.4.w4)
  • Once they are accepting or welcoming of being stroked, gently pick up each kit in turn, with one hand around the chest and the other supporting under the back end, ensuring its weight is well distributed and supported. (B651.4.w4)
Bonobo consideration It is highly desirable that an infant bonobo should remain with its mother and be raised by her. (B437.w24, D386.3.1.w3a)
  • Parent-reared bonobos are thought more likely to successfully breed and rear their own offspring than are hand-reared individuals. (B437.w24)
  • Inexperienced primiparous mothers should be given guidance, for example by keepers demonstrating the correct way to hold an infant, when the bonobo is in the last quarter of pregnancy. (D386.3.1.w3a)
  • Consider the group dynamics are whether, for example, an individual which has previously been known to injure infants, should be separated from the group containing the dam in the time before the expected birth date. (B23.50.w50)
  • If there are no obvious physical threats to the infant's safety, and its general health appears good, the mother should be given as long as possible, even up to 72 hours, to develop a bond with her infant and start caring for it properly. (D386.3.1.w3a)

Positive signs for initial infant health and development include:

  • no obvious medical or physical problems.
  • the mother holding the infant (even if not in the correct position for the first few days).
  • the infant is breathing.
  • the infant is moving its head and limbs.
  • the infant is gripping onto its mother with at least one limb. They should start to grip within the first few day, even if not always immediately after birth, and should try to grip when awake, even if not always gripping while asleep).
  • the infant is seen nursing (usually begins within the firs day, but occasionally is not seen in the first few days) certainly within 72 hours of birth. Expect initial nursing bouts to last one to two minutes.
  • the infant is vocalising, and the mother is responding appropriately, for example by picking the infant up, or repositioning the infant).
  • The mother is showing an interest in the infant and grooms it properly.
  • The mother is carrying the infant (inexperienced mothers do not always hold their infant upright initially).
  • The infant is urinating and defecating.

Negative signs include:

  • The mother does not show any interest in her infant.
  • The mother pokes or prods the infant, but doesn't pick it up.
  • After the first 72 hours, the mother is still holding the infant in a position from which it cannot nurse.
  • Other bonobos are carrying the infant and the mother is not trying to retrieve it from them
  • The mother puts the infant down and does not return when it vocalises (primiparous mothers may do this on one or two occasions)
  • in the first 24 hours, the infant is not seen to move (note, if the mother is reclusive, it may be very difficult to observe the infant).
  • All four of the infant's limbs dangle for long periods (e.g. more than three hours).
  • The infant hangs its head for long periods when awake.


  • If the basic problem is that the infant is not nursing, after 72 hours the infant can be removed, bottle fed for up to a day, after which it should be returned to its mother if possible to see if she responds properly. (D386.3.1.w3a)

Associated techniques linked from Wildpro

  • --


Return to top of page

Foster Rearing

If a female animal is unable or unwilling to rear her offspring, it may be possible to foster the infant onto another female. 
  • How easy this is to achieve depends to a large extent on the system used for infant-mother recognition in a given species. Often, smell is important. This may be fooled by separating the mother from her own offspring and mixing them with the foster young for a period of time, to share scents, before letting her back.
  • It is preferable to foster an infant onto another female of the same species, to remove the possibility of imprinting onto the wrong species and poor integration into the correct species at a later date.
  • Fostering onto related domestic animal species (e.g. dogs, cats, goats, cattle, horses) can be used.
    • Fostering onto a goat can be particularly useful for hoofstock which have suckled from their dam initially and will not accept a bottle.

Dominant females "kidnapping" young

  • Problems sometimes arise within a social group or herd in which a subordinate female gives birth while a dominant female is heavily pregnant. In such cases, the dominant female may "kidnap" the infant and start to raise it. Sometimes this occurs unobserved by the care takers and the situation becomes clear only when the dominant female produces her own offspring. At this time she may try to rear both or only one. It may be too late to return the first infant to its real mother.

(B429.4.w4, V.w5)

Bear Consideration

  • Bears in the wild do sometimes adopt cubs. However, attempts to promote fostering in the wild have often been unsuccessful, with cubs sometimes being killed by the female. Adoption is most likely to occur when the cubs (the female's own and the cub to be fostered) are very young, before they would normally exit the den. After this time, the female appears more able to recognise the other cub as not her own. (B285.w4, D243, J59.12.w1, J343.49.w1, J343.52.w2)
  • Fostering of older cubs in the wild is more likely to be successful if the female is immobilised and her sense of smell temporarily impaired (e.g. by placing Vicks "Vapo Rub" in her nostrils), or if the orphan is placed with the female's own cubs for at least two hours before she is allowed back to the cubs. (J59.12.w1, J332.65.w1)
    • Keeping the mother from the cubs for two to seven hours has been achieved by "treeing" the bears, placing the orphans into the trees, then keeping the mother from returning to the cubs for two to seven hours. (P62.4.w2)
    • Rubbing Vicks "Vapo Rub" onto the orphan before presenting it to the female has been found to effectively inhibit aggression from the female. (P62.4.w2, P62.8.w1)
  • Note: A female with an extra-large litter due to adoption may lose all the cubs, particularly is she is in poor nutritional condition. (J332.44.w1, P62.4.w2, P62.8.w1)
    • In areas where food is not plentiful, cub survival is reduced as litter size increases even in natural litters. (P62.4.w2)
    • A female Ursus americanus - American black bear with six cubs (four her own, two adopted), with access to human-associated foods, successfully reared the cubs. (J59.12.w1)
    • Survival of large litters with adopted cubs is likely to be reduced in suboptimal habitat. (J59.14.w1)
  • If fostering of one or more cubs to a wild female will result in a large litter size, it may be necessary to provide supplementary food in the female's territory to improve survival of all the cubs and reduce the risk that none will survive. (J59.14.w1, P62.4.w2, P62.8.w1)
    • Food provided should be in a form and manner which will not subsequently be associated with humans. (J59.14.w1P62.4.w2)
    • Replacing male cubs with orphaned female cubs could be considered in situations where population numbers are low and population viability is threatened, since it is survival of females which is most important to increase population size. (J59.14.w1, P62.4.w2)
  • Deliberate fostering of Ursus maritimus - Polar bear cubs in the wild requires much effort to find a suitable foster family, capture the family, place the cub for adoption and follow-up the family afterwards. Success following such fostering has been poor. (D259.VIII.w8)
  • Fostering in captivity may be limited by not having a suitable female with cubs to whom the cub(s) could be fostered. (V.w5)
  • At Amsterdam Zoo, where three female Melursus ursinus - Sloth bears bears all cubbed and two females each successfully reared one cub, after emergence from the dens, both cubs were observed sucking from a single female. (B437.w36)
Interspecific foster rearing
  • Black bear cubs in a zoo have been cross fostered successfully, at least twice, onto an Ursus arctos - Brown bear which was rearing cubs. (J339.20.w1)
  • Fostering of bear cubs onto a large domestic dog could be considered. (J23.22.w1)
    • Fostering of a black bear cub, from about four weeks to about seven weeks of age, onto a 19 kg cross-bred domestic bitch has been described. The cub was then kept with one of its foster litter-mates (i.e. a domestic dog pup) for about a further 6.5 weeks before being placed with other orphaned bear cubs. There were no problems in its integration with the other cubs and no unusual behaviours were noted. (J23.22.w1)
    • Cross-fostering onto an appropriate bitch requires less intensive human care than does hand-rearing. (J23.22.w1)

Lagomorph Consideration 

Fostering is an alternative to hand-rearing of rabbit kits or leverets if a foster female, capable of suckling the young, is available. In general, fostering is carried out to another female of the same species. However, cross-species fostering has also been carried out successfully.
  • It is likely that the success of fostering may be affected by the temperament of the individual female, particularly for cross-fostering and fostering of young of a different developmental stage to the female's own kits.
  • Placing a drop of scent such as pine-oil on the foster doe's nose is sometimes suggested to reduce the risk of rejection. (B10.45.w47, B64.22.w8)
Domestic rabbit
  • Rabbit kits can be cross-fostered onto another doe. (B550.16.w16, B614.2.w2) Cross-fostering is preferable to hand-rearing, if another lactating doe is available. (B338.1.w1, B618.21.w1) 
    • Fostering is used commonly in commercial situations, for example to make litters more evenly sized for suckling. (B550.16.w16)
    • Fostering is also used if milk let-down fails, since the young will otherwise die in two to three days. (B550.16.w16)
    • Generally a female can suckle up to eight young adequately; more than this and they will be underdeveloped at weaning age. (B550.16.w16)
  • When a female has her own litter and more kits are to be added, fostering can be carried out simply by placing the kits in the nest while the female is away. Since she normally visits the kits only once a day, for a few minutes, it should be relatively easy to carry this out. To minimise disturbance and the risk of the female rejecting the kits due to their strange scent, the kits should be rubbed with the nest bedding and place them at the bottom of the litter, camouflaging their scent. (B602.13.w13)
  • Note: Do not foster young onto another doe if their own mother had an infectious disease such as Bacterial Mastitis in Rabbits as infection may be transmitted to the foster doe via the kits. (B10.45.w47, B609.2.w2, J296.62.w2, B618.21.w1)
  • Does with very young kits are most likely to accept foster kits; very calm does may accept kits fostered later. (B618.21.w1)
  • Foster to a doe with kits of the same age (or as close as possible). (B550.16.w16, B618.21.w1)
    • If necessary, they may be up to three days apart in age. (B550.16.w16)
  • Ideally, transfer kits in the first few days; fostering can be carried out at up to two weeks. (B550.16.w16)
  • Kits are added while the female is out of her hutch, and she is then returned, given tit-bits and observed. (B550.16.w16)
Wild lagomorphs
  • Hare leverets (Lepus spp.) can be fostered onto other females. Observations of both Lepus europaeus - Brown hare and Lepus americanus - Snowshoe hare have noted occasional suckling of leverets by the wrong female (when different litters were born less than 40 m apart), suggesting that females of these species may not identify their own leverets, but simply suckle leverets which present themselves for suckling. (J46.191.w1, J343.40.w1)
  • In captivity, fostering of Lepus americanus - Snowshoe hare leverets from one female to another was not found to be a problem, and one female who had lost all her own young then reared an adopted litter of a similar age. Females were not given excess leverets - none had to suckle more than four or five leverets. (J40.9.w1)
  • Same-species and cross-species fostering has been recorded with a female Sylvilagus audubonii - Desert cottontail. The rabbit was brought to a rehabilitation centre with a pelvic injury and had apparently recently littered, based on the fact that her nipples were enlarged. The female was kept in a rehabilitation centre for several weeks while recovering from her injury, and acted as a surrogate mother several times: (J417.24.w3)
    • 1) While being given floor exercise, she unexpectedly accepted three 2.5 week old weanling cottontails (same species), allowing them to nurse.
    • 2) When placed in a box with neonatal cottontails, she smelled them, moved to a corner, but then allowed them to approach and suckle. While they nursed, she sniffed and groomed the faces, ears, legs and bodies of the kits, vigorously stimulating them. She let them suckle for about 10 minutes, then moved to the far end of the box and produced both normal faecal pellets and caecotrophs, which the kits were seen sniffing and later nibbling. The female also ate both fecal pellets and caecotrophs. She was placed with them daily, with the kits suckling for about 10 minutes. In their second week, she allowed more contact, letting them lie under or next to her after suckling. By the end of the third week, she would decide when they had suckled enough and would get up and refuse to allow further nursing. Once sh no longer was willing to nurse the young, she was no longer placed in their box.
    • 3) When placed with two neonates admitted with bloat and diarrhoea, she sniffed them intently then stimulated them for longer than with normal kits, until they eliminated large amounts from their gastrointestinal tract and finally produced a clear liquid. Their GIT function subsequently appeared normal.
    • 4) A neonatal Lepus californicus - Black-tailed jackrabbit was initially being hand-reared. When placed on the floor at the same time as the adult female was exercising, the jackrabbit approached the female and started suckling. Initially she moved away, but then allowed it to suckle. The youngster was placed with the female twice a day, and suckled from more than one nipple at each feeding. The female groomed and stimulated the jackrabbit, dropped caecotrophs and faecal pellets for it (which it ate), and allowed it to have physical contact with her after nursing. She allowed it to nurse for three weeks, then stopped letting it suckle, as she had done with the cottontails. It was then hand-fed and gradually weaned by the middle of the sixth week.
    • Note: the female cottontail was given plenty of food including water, timothy hay, alfalfa hay, leaves and twigs of mesquite trees (fresh), kale and deer grass, with small amounts of carrot and oats. She was also given warmed mixed Zoologic Milk Matrix, fresh goat's milk and Oxbow Critical care, drinking 20 - 40 mL of the mixture each day. Having improved clinically, she was released about six weeks after release of the last rabbit she had sucked.


Ferret Consideration Ferret kits can be fostered onto another jill. (B338.26.w26, B651.6.w6) It is preferable if the kits are close together in age (B651.6.w6), preferably no more than a week apart, as otherwise the larger, stronger kits can push the smaller kits away. (B338.26.w26)
  • This is the preferred option if, for whatever reason, the jill is unable to rear her own kits. (B338.26.w26)
  • To place the foster kits with the jill's own litter, provide food for the female, away from the nest - give a sloppy/liquid food which she must eat where it is, not bring back to the nest - then mix the kits, quietly adding the extra kits and placing bedding on them to disguise any different smell. (B627.8.w8, B651.6.w6)
  • Jills have eight nipples; they can rear more kits than this, rotating them to nurse, (B338.26.w26) but do not add too many kits or the female will be unable to rear them. (B651.6.w6)
  • If a litter is small (less than five kits) it is advisable to add kits to the litter so that there is sufficient stimulus to mainatin lactation properly. (B627.8.w8)
Bonobo Consideration Foster-rearing is the next most preferable option after mother-rearing. The infant should be fostered to another female who has shown maternal behaviour towards infants and juveniles. (D386.3.1.w3a)
  • Fostering to another lactating female bonobo was successful at Milwaukee Zoo. (D386.3.1.w3a)
  • It may be possible to foster to a non-lactating female if the foster mother is willing to allow the keepers to bottle-feed the infant. (D386.3.1.w3a)
  • It may be necessary to consider moving the infant to another institution if a potential foster mother is available there. (D386.3.1.w3a)

Associated techniques linked from Wildpro

  • --

Return to top of page


NOTE: Decisions regarding whether or not an abandoned/orphaned neonate, or litter, should be hand-reared, must be made based on considerations such as the genetic value of the animal, and the likelihood of behavioural problems developing. It is also necessary to consider whether resources are available (including personnel time) to complete the hand-rearing process and to either re-integrate the animal into a group of conspecifics or release it back to the wild. (V.w5)
  • For any managed species (EEP, SSP, ESB etc.), if a situation arises in which parent-rearing or same-species foster-rearing cannot occur and hand-rearing is considered, the programme coordinator or studbook keeper for the species should be consulted. For genetically important animals, their value may outweigh potential behavioural and breeding problems due to hand-rearing. Where available, consult management guidelines for the species regarding hand-rearing. (V.w104)

Hand-rearing should never be the first choice option; parent-rearing is always to be preferred.

  • Hand-rearing risks the animal growing up to be behaviourally abnormal in its responses both to humans and to conspecifics. This is more of a problem in some species than in others.
    • Hand-reared antelope and deer may be seriously dangerous to humans when playing, and particularly during the rutting season.
    • Hand-reared individuals may be incompatible with conspecifics.
    • Hand-reared individuals may show poor breeding.
    • Hand-reared females may not show normal maternal behaviour.
Hand-rearing may be required due to:
  • Death of the mother.
  • Serious illness of the mother.
  • Lack of or insufficient milk production by the mother, combined with a situation in which supplementary feeding is not possible.
  • Rejection of the young by the mother.
  • Illness, injury or congenital problems of the neonate.
  • Interference in the rearing process by other members of the mother's social group.
  • Requirement for specific pathogen free animals for reintroduction, from a herd with a serious infection problem.
  • Inappropriate enclosure or environmental conditions for rearing young.
    • This situation should be avoided when possible by moving the female or social group to an appropriate environment. However, incidents such as extreme bad weather which may interfere with parent-rearing may not be predictable.

Risks of the development of abnormal behaviours in hand-reared animals may be reduced by:

  • Minimising human contact (visual, auditory, tactile, scent).
  • Limiting contact to one or two specific humans, rather than humans in general.
  • Rearing in a group with conspecifics (other neonates), or with exposure to older animals of the same (preferably) or a similar species from an early age.
    • When the mother is not producing milk (or producing insufficient milk) or not allowing suckling (e.g. due to mastitis), it may be possible for the infant to remain with its mother/group while being bottle fed. Care must be taken to ensure it is getting adequate shelter, warmth, toileting/elimination (if required), and that it is not injured by dominant animals in the group. (B429.4.w4, V.w5)

Important aspects of hand-rearing include:

  • Warmth and ventilation .
    • Warmth and protection from draughts is particularly important for altricial infants.
    • If temperature is not maintained at an adequate level, the feed (suckle) response may be lost. (V.w106)
    • The temperature at which altricial infants are kept should be monitored closely, using an appropriate thermometer placed at the same level/height as the infant. (V.w5, V.w106)
    • Note: Incubators should be checked (by running them at the temperature at which they will be used) before they are required (e.g. a month before the expected birth season of seasonal breeders). (V.w106)
    • Neglected infants may be chilled when first presented. See: Chilling - Hypothermia
  • Food; initially, milk.
    • Note: the first feed should usually be oral rehydration solution, rather than milk. This is less likely to cause problems if the infant fails to swallow properly and some liquid goes down the trachea (windpipe) while it learns to suckle from the bottle. (V.w5)
    • Consideration should be given to the milk composition of the species, if known, and allowing for changes at different stages of lactation. However, a consistent formula (i.e. one that is mixed the same each time, not varying in concentration) and good hygiene may be more important than the exact composition. (P17.24.w1)
    • Lactose-free milk (which can be produced by treating milk with lactase enzyme) may be required for some species in which the natural milk is very low in lactose.
    • Intake must be sufficient to meet the infant's nutritional requirements, divided into enough meals that the stomach is not overfilled.
      • Species with young carried by the dam, or the dam always available for the young to nurse, tend to have relatively dilute milk and frequent consumption of small quantities of milk. In contrast, species in which the young are left alone with the mother returning at infrequent intervals to nurse them tend to produce concentrated milk with a high fat content. (P1.1972.w1)
    • Rehydration may be needed initially if the infant has been neglected and is dehydrated. See: Treatment and Care - Fluid Therapy
  • Hygiene and disease control.
    • A high standard of hygiene is particularly important for infants of species which normally receive most of their antibodies from colostrum and have not had the opportunity to suckle any or sufficient colostrum from their mother.
    • Consider giving subcutaneous and possibly also oral serum from an adult animal of the same species, preferably one at the same location.
      • Absorption of immmunoglobulins from the gastrointestinal tract occurs probably only for about 12 - 16 hours in carnivores, based on data for domestic cats and dogs. After this time, parenteral administration (e.g. subcutaneous) is needed to increase circulating immunoglobulin levels. Oral administration after this time will increase local immunoglobulin levels, but not systemic levels. (P106.2007.w6)
      • In domestic cat kittens, parenteral administration of 150 mL serum per kilogramme bodyweight was found to produce normal serum IgG concentrations. (J4.219.w6)
      • Consider giving heterologous colostrum (e.g. stored bovine colostrum for ungulates) to animals which have not received colostrum from their mother. (B10.3.w18)
    • All feeding implements should be washed and thoroughly rinsed after each feed, and sterilised at least once a day following washing. (B468.8.w8g)
  • Toileting/elimination and burping.
    • Many mammals require stimulation to urinate and defecate, at least initially. The time for which such stimulation is needed varies with species.
    • Burping may also be required.
  • Security/substitute "mother".
    • This may take the form of an artificial pouch (e.g. for marsupials), or a soft toy to cling to (e.g. for primates).
  • Rest.
    • Between feeds, young animals need rest; they should not be disturbed to be "shown off".
  • Records.
    • Records of weight (measured at the same time each day), food intake (type of milk, amount, number of feeds), and developmental milestones (e.g. eyes and ears opening, tooth development, first walking, for altricial species) are important both to monitor the progress of the individual and for comparison and assistance with rearing subsequent infants.
    • Scales used should be calibrated yearly. (V.w106)

(B10.3.w18, B105.19.w6, B429.4.w4, B438.24.w24, J4.219.w6, P1.1972.w1, P17.24.w1, V.w5, V.w106)

Notes on milk replacers: 

  • Many milk replacer formulas mention Esbilac, KMR, Multi-Milk and Zoologic Milk Matrix. These are all produced by PetAg and are widely used. The following general information may be useful.
    •  Esbilac is a milk replacer designed predominently for domestic dogs. In 1993 the formulation changed and a small amount of butterfat was added; this made cleaning of feeding implements more difficult (greasy residue).
    • KMR is a milk replacer designed for domestic cats. It contains a higher level of protein and less fat than Esbilac. Like Esbilac, in 1993 the formulation changed and a small amount of butterfat was added; this made cleaning of feeding implements more difficult (greasy residue).
    • Multi-Milk is a lactose-free milk replacer; if may be used alone or in combination with other Pet-Ag milk replacers.
    • Zoologic Milk Matrix is a range of milk replacers designed for use with wild and exotic mammals.
      • Milk Matrix 33/40 is equivalent to the original (pre-1993) Esbilac, and does not include butterfat.
      • Milk Matrix 42/25 is equivalent to the original (pre-1993) KMR and does not contain butterfat.
      • Milk Matrix 30/55 is equivalent to Multi-Milk.


  • Another company producing a range of milk replacers for wildlife is Fox Valley Animal Nutrition. (B468.8.w8e)
  • Adding heavy cream (whipping cream) to a milk increases the percentage fat in the formula. It also will decrease the percentage protein and change the percentage lactose and the energy content. (B468.8.w8f)

Further information on hand-rearing is provided in: Hand-rearing of Orphaned Wildlife (with special reference to UK Wildlife)

Bear Consideration

Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption

Bears of several species have been hand-reared successfully, including Ursus americanus - American black bear, Ursus arctos - Brown bear, Ursus maritimus - Polar bear, Helarctos malayanus - Sun bear and Tremarctos ornatus - Spectacled bear. (J23.4.w1, J23.9.w5, J23.16.w6, J368.11.w1, D252, D253.w1)

Bear cubs should not be hand-reared routinely and it has been suggested that polar bear cubs should be hand-reared only as a last resort (J23.14.w3). However, hand-rearing may be considered necessary in captive bears if the mother is clearly neglecting her cubs, and may be needed for orphaned or abandoned wild bear cubs.

  • If a single cub needs to be hand-reared (e.g. an orphaned wild bear cub), it is preferable to find another cub of about the same age/size and rear the cubs together; this may require moving one cub between rehabilitation facilities. (P62.9.w1)
  • The EEP Ursid Husbandry Guidelines state that hand-rearing of captive-bred cubs is not recommended. (D247.6.w6)
  • For any managed bear species, consult management guidelines if available, and contact the species coordinator or studbook keeper regarding whether, due to their genetic value, the cub(s) should be hand-reared. (V.w104)
  • Note: Whether hand-raising from the very first days of life can be considered as a useful tool for zoo bears, will be re-considered after careful analyses of studbook data of all bear species with respect to breeding and rearing success of hand-reared animals, and of their dams after these experienced removal of cubs for hand-raising. Empirically collected data on the behavioural development and integration of hand-raised bears into a breeding group are other aspects which have to be checked, as well as predictions which can be made from information on social learning in solitary species with altricial young, like bears. (V.w107)

General considerations:

  • Young cubs must be kept warm and dry. (B288.w11)
  • Cubs should initially be kept in an incubator at 31 C (88 F) and 40% humidity. (B16.9.w9, B64.26.w5)
  • Strict hygiene, including good hygienic practice when preparing milk formula, is essential for very young cubs (e.g. those being reared from birth or from only a few days old). (B16.9.w9, B64.26.w5)
  • Serum immunoglobulin supplementation may be required for cubs hand reared from shortly after birth, both subcutaneously to raise systemic IgG levels, and orally to improve local immunity in the gastro-intestinal tract. (P106.2007.w6, V.w106)
    • Based on data from domestic cats, 7.5 to 15 mL of serum should be given per 100 g bodyweight. This can be collected in advance and stored frozen. Ideally, serum from the mother is given. (V.w106)
    • In domestic cat kittens, parenteral administration of 150 mL serum per kilogramme bodyweight was found to produce normal serum IgG concentrations. (J4.219.w6)
  • Cubs require stimulation of the anal area with a warm damp cloth in order to urinate and defecate. (B16.9.w9, B64.26.w5, P85.1.w4, P85.1.w8)
  • Weigh cubs daily initially. (P62.9.w1)


  • Feeding of bear cubs is similar to feeding other carnivore cubs. (P62.9.w1)
    • Young cubs need to be bottle-fed. (P62.9.w1)
    • Bear cubs must be fed lying on their front with the head slightly elevated holding the nipple of the bottle. A bear cub fed lying on its back may inhale milk which could lead to aspiration pneumonia. (B123.19.w19)
  • Initially give rehydration solution in the first feed and gradually change over to milk formula. (P62.9.w1)
  • Maintain sterility and avoid overfeeding. (P62.9.w1)
  • Up to 2-3 weeks of age, feeds every two hours are required, with about 14-20 mL given per feed. (B16.9.w9, B64.26.w5)
  • Start weaning once the cub's eyes are open and the cub is seeing properly, at about six weeks of age. (P62.9.w1)
  • Cubs can be totally weaned onto semi-solid or solid food by about four months of age. Cubs which present for rehabilitation at this age can be weaned. (P62.9.w1)

Further details are provided in:

Hand-Rearing Wild-born cubs for Release

Opinions differ regarding the advisability of releasing hand-reared bears. There are species and individual bear differences which must be taken into account when deciding whether release is a viable option. (B432.w1, B432.w3, D270.I.w1, V.w101

  • Release of hand-reared cubs must consider the ability of the cub to find food, construct a den in a suitable site, and survive hibernation and initial emergence from the den the following spring. The cub should have a proper fear reaction to humans (not be habituated) in order to reduce the risk of its becoming a nuisance bear. Additionally, the potential impact on the population into which it is being released must be considered, including risks of importing disease picked up while the cub was being cared for. (B432.w6, 270.VII.w7, D270.IX.w9, D270.X.w10, P62.4.w2, J15.20.w3)
  • Bears hand-reared and released as cubs, yearlings and two-year-olds have survived following release into the wild. (P62.4.w2)
  • The US Fish and Wildlife Service does not recommend the release of hand-reared orphaned Ursus maritimus - Polar bear cubs, noting that "Hunting and survival skills are learned during the 2 year dependence on the mother, are not innate to polar bear cubs, and will not be developed in captivity." (D259.VIII.w8)

Key elements for successful reintroduction of hand-reared cubs to the wild include:

During rearing:
  • The opportunity to socialise with other bear cubs during early development. (D252.w29)
  • Minimising the amount of contact with humans, and minimising the number of caretakers during rearing, particularly after weaning. (D270.X.w10)
    • Frequent contact between cub and caretaker is required in young cubs being bottle fed, and bottle-fed cubs may continue to show dependence on their caretaker for a period after weaning. However, over time they become more independent and, particularly if other cubs are present to interact with, show less interest in their caretakers. Independence increases as cubs reach the age of normal family break-up in the wild. (D270.VII.w7)

Release site & timing

  • Release into adequate, high-quality habitat. (D252.w29, D270.X.w10)
  • Release with sufficient fat reserves to cover the bears over the initial adjustment to their new surroundings. (D270.X.w10)
  • Release when natural foods are abundantly available. (D270.X.w10)
    • Survival of cubs post-release may be dependent on food availability. (P62.4.w2)
  • Time the release to minimise the chance that the bears will encounter people in the immediate post-release period. (D270.X.w10)
    • Minimum contact with humans in the first 7 - 10 (D252.w29) first 14 days after release. (D270.VIII.w8)
    • Bear cubs released following hand-rearing should be released into remote areas if they have become tame, to reduce the risk that they will become nuisance bears. (P62.4.w2)
  • Release bears at an age similar to the normal time of family break up. (D270.X.w10)
  • Note: The individual personalities of the bears affects the success of release. (D252.w29, D270.IV.w4)
    • Bear cubs are individuals and have individual personalities; suitability for release may have to be assessed at the time for release. (D270.I.w1)
  • Releasing hand-reared Ursus arctos - Brown bear is more likely to result in the creation of problem bears than is the case with other bear species such as Ursus americanus - American black bear. Hand-reared brown bears should be released only if this can be carried out in a vast area without people. (V.w101)

Lagomorph Consideration 

Hand-rearing a pygmy rabbit. Click here for full page view with caption Click image for full page view Click image for full page view Feeding leveret. Click here for full page view with caption Feeding leveret. Click here for full page view with caption Small cage for leveret. Click here for full page view with caption Outdoor run for leverets. Click here for full page view with caption

Hand-rearing of lagomorphs is generally considered difficult. (B10.45.w47, B601.1.w1, B606.6.w6, B618.21.w1)
  • In particular, there may be problems in developing the normal gut flora. (B618.21.w1)

Hand-rearing may be needed:

  • If the female nests in an unsafe place (for example in the enclosure of a carnivore) where the young are at high risk of predation. 
  • If the female is known to be dead. (B338.1.w1, B602.13.w13)
    • (e.g. a hare found dead on the road with a live leveret beside it). (J23.28.w1)
  • If a pre-weaning individual has been found injured and is suitable for treatment and rehabilitation. (B338.1.w1)
  • If the female has poor mothering ability (e.g. a doe with her first litter). (B338.1.w1, B601.1.w1, B602.13.w13)
    • If the female does not feed the kits for 48 hours, this confirms mismothering. (B601.1.w1)
    • Cannibalism and desertion are more likely to occur with primiparous, stressed or overcrowded does. (J29.10.w2)
  • If the female is definitely not lactating. (B601.1.w1)
    • Note: the start of lactation may take 24 hours after parturition. (B601.1.w1)
  • If a nest of young is known to have been abandoned (e.g. with an escaped/feral female Oryctolagus cuniculus domesticus - Domestic rabbit. (B338.1.w1)
  • If the kits have thin abdomens (no milk) and wrinkled skin (dehydrated) this indicates lack of feeding. (B601.1.w1)
  • If the doe has mastitis (Bacterial Mastitis in Rabbits); fostering is not recommended as infection may be spread to the foster doe(s). (J29.10.w2)
  • Note: If possible, use the option of fostering - see above.
Assessment, initial care and stabilisation
It is important to assess neonates when they arrive for hand-rearing.
  • Assess for any injuries, checking carefully for puncture wounds from animal bites, which may not be immediately evident. (B338.1.w1)
    • Assume that any cat-caught infant has been infected with Pasteurella; start appropriate antibiotic treatment immediately (J417.12.w1) (see: Pasteurellosis in Lagomorphs)
    • If in an area where Rabies is present, consider the risk that the bite would is rabies-virus contaminated. (B338.1.w1)
    • For free-living lagomorphs, before starting to hand-rear, consider whether injuries (e.g. fractures, eye injuries) will result in permanent impairment which would reduce the chances of survival after release. Wild lagomorphs rarely become tame and may suffer chronic stress if maintained in a captive situation. Euthanasia may be the most humane option. (B338.1.w1) See:
  • If the neonate is cold (Chilling - Hypothermia), it needs warming. (B338.1.w1, B602.13.w13)
    • Normal temperature is about 37.8 - 39.4 C (100 - 103 F) for most rabbits and hares. (B338.1.w1)
    • Unsuckled rabbit kits remain normoglycemic to six hours post-partum; the glycogen stores are then exhausted. (B612.8.w8)
    • If the neonate has a body temperature reduced by 3 - 4 C (5 - 6 F), re-warm by immersing in warm water (37.8 C/100 F) keeping its head out of the water and massage it gently, for up to five minutes. Then take it out of the water and keep it warming under a heat lamp of drier. (B338.1.w1, J417.18.w1)
      • Be very careful not to burn the youngster on the heater.
      • Note that with severe hypothermia the initial warming may not return its body temperature to normal. Too rapid warming should not be carried out; this may lead to fatal metabolic changes. (B338.1.w1)
  • Note: The infant may also be dehydrated and warming may make any dehydration of the neonate worse. After initial warming, give fluids. (B602.13.w13, B338.1.w1)
    • Fluids should be isothermic, i.e. warmed to 37.8 C (100 F). (B602.13.w13)
    • Lactated Ringer's solution is appropriate. (B602.13.w13, B338.1.w1)
      • Or for a weak, probably hypoglycaemic individual, 2.5% dextrose in lactated Ringer's solution. (B338.1.w1)
    • Give 10 - 15 mL per 100g body weight subcutaneously. (B602.13.w13); up to 35 - 40 mL/kg per day can be given. (B338.1.w1)
  • With eyes-closed neonates, stimulate to urinate, as they may not be able to urinate without such stimulation. (J417.18.w1)

Tube feeding

Weak neonates may need their first feed or two given by tube. (B601.1.w1, B602.13.w13, B338.1.w1)

  • A nasogastric tube can be used. (B602.13.w13) Red rubber catheter attached to a 3 - 5 mL syringe. (B338.1.w1)
  • Premeasure the catheter from the end of the neonate's nose to the last rib and make a mark with indelible ink on the catheter at this point from its tip. (B338.1.w1)
  • Fill the syringe with milk (warmed to body temperature) and advance the plunger until milk is visible at the tip of the catheter. (B338.1.w1)
    • If milk comes out through the end of the catheter, wipe off the excess. (B338.1.w1)
    • The amount of milk should be about 70 - 75% of the expected feed volume if the infant was suckling. (B338.1.w1)
  • Pass the tube through the mouth and gently advance it down the oesophagus as the infant swallows until the mark reaches the tip of the mouth. (B338.1.w1)
    • If the catheter had entered the trachea it should not be able to pass that distance (unless taken forcibly through the lungs and diaphragm). (B338.1.w1)
  • Slowly press on the plunger to administer the formula. (B338.1.w1)
    • If there is resistance, stop. (B338.1.w1)
    • The abdomen should be gently distended, not firm or hard, after feeding. (B338.1.w1)
  • See also: Orogastric Tube Placement in Rabbits


  • This should be carried out for the first week in rabbits; after this time it is generally not required. (B602.13.w13)
  • Stimulate the peritoneal area with a damp cloth or cotton wool after each feed for about 10 -14 days old. (B601.1.w1)

Feeding utensils

  • A syringe or a kitten feeding bottle can be used. (B606.6.w6)
  • Feeding by syringe generally results in less feed being given, therefore more frequent feeding may be needed. (B606.6.w6)
  • If a syringe is used then the suckling reflex may be lost after two days. and syringe feeding cannot be replaced by bottle feeding at that stage. (B606.6.w6)


  • Keep young wild lagomorphs in a quiet place. (B284.10.w10)
  • They should be kept warm and dry. (B284.10.w10)
  • Provide bedding material into which they can burrow, such as a towel or shredded tissue paper. (B284.10.w10)
  • Either place the box in a warm environment (e.g. in an airing cupboard) or use a heat mat under the box. (B284.10.w10)
  • Keep young kits at 27 - 30 C (80.6 - 86 F), in a small box lined with hay and rabbit fur (if available) or with soft tissues or cotton rags. (B606.6.w6)
  • Initially (first week) maintain orphaned rabbits in an ambient temperature of 26.7 - 29.4 C (80 - 85 F), then gradually reduce the temperature to reach 21 - 23.9 C (70 - 75 F) by the third week. (B338.1.w1)
  • The initial higher temperatures may not be required for leverets, as they are precocial, fully furred and more able to self-regulate body temperature from an early age. (B338.1.w1)
Milk and milk replacers
  • Lagomorph milk is high in fat and protein and low in carbohydrates. (B602.13.w13)
    • The composition of milk changes over the course of lactation, with higher fat values towards the end of lactation, while protein decreases, being highest in colostrum. Lactose is constant and low. (B602.13.w13, J301.58.w1)
  • The following values are available:
  • Available milk replacers are less rich than lagomorph milk, therefore greater quantities are required per day. This is achieved, without overloading the stomach, by giving more than one feed per day rather then the single feed given by the doe. (B284.10.w10, B606.6.w6)
Example milk replacers for lagomorphs:

A variety of milk replacers have been used for lagomorphs. The diversity probably reflects variation in availability of different products, differences in lagomorph species' reactions to different milk replacers, and personal experiences of different people carrying out 

  • 6 parts Esbilac (PetAg, Inc.) liquid, 4 parts Multi Milk powder (PetAg, Inc.) (contains 1.91 kcal per mL). (B338.1.w1, B602.13.w13)
  • 1 part Esbilac powder, 1 part Multi Milk powder, 1.5 parts water (contains 2.01 kcal per mL). (B338.1.w1, B602.13.w13)
  • 2 parts KMR liquid (PetAg, Inc.), 1 part Multi Milk powder (contains 1.73 kcal per mL). (B338.1.w1, B602.13.w13)
  • 1 part Esbilac powder, 0.25 parts heavy cream, 1 part water (contains 1.93 kcal/mL). (B338.1.w1, B602.13.w13)
  • 1 part evaporated milk, 1 part water. To each cup of mixture add 1 egg yolk and 1 tablespoon of corn syrup. (B338.1.w1, B602.13.w13)
  • Whole cows milk 25 mL, condensed milk (18% butterfat) 75 mL, lyophilised skimmed milk powder 6 g, vitamin supplement. (B618.21.w1)
  • Milk replacers designed for kittens. (B614.2.w2)
  • Esbilac puppy milk replacer (Pet Ag). (B151, B284.10.w10, D24, J34.9.w1, P3.1987.w3)
    • Make up at one part powder to two parts water. (B284.10.w10)
  • Welpi puppy milk replacer (Hoechst UK Ltd.), mixed one part powder to two parts warm water, with 0.3 mL multivitamins (Abidec, Parke-Davis) added once daily. This has been used for Lepus europaeus - Brown hare from about two days old. (J23.28.w1)
  • Esbilac (Pet Ag), possibly with egg yolk to increase fat and protein, or with added Multi-Milk (Pet-Ag, Illinois). (B156.12.w12)
  • KMR or Esbilac (Pet Ag), possibly with added egg yolk (P19.1.w5), or Multi-Milk (Pet-Ag, Illinois).
  • Goats milk or lamb milk replacer. (D25)
  • Cimicat (Hoescht). (B284.10.w10)
    • Make up at one part powder to two parts water. (B284.10.w10)
  • Cimicat (Petlife International Ltd., Bury St Edmunds). (W730.Dec08.w1)
    • One part powder to three parts boiled and cooled water. (W730.Dec08.w1)
      • 0.5 - 1.0 mL Abidec multivitamins added
  • Goat's milk. (B284.10.w10)
  • Goats milk - fresh or fresh-frozen - for Lepus californicus - Black-tailed jackrabbit leverets. (N35.12.w1)
  • Ewe's milk substitute such as Lamlac, mixed as per the manufacturer's instructions. (W729.Dec08.w1)
  • Cow's milk with added vitamins has been used successfully to rear black-naped hare (Lepus nigricollis - Indian hare) leverets. (J23.35.w2)
  • Half cup canned evaporated milk, one egg yolk, half a cup water, one teaspoon of honey, one teaspoon of Abidec baby vitamins. Consider adding a little 90% protein powder. (B64.22.w8)
  • 120 mL water, 120 mL canned evaporated milk, 15 mL Karo syrup (used successfully for Lepus californicus - Black-tailed jackrabbit). (B64.22.w8)
  • Note: 
    • A mug-warmer in which the milk substitute can be kept at the right temperature during each feeding can be very useful. (W730.Dec08.w1)
    • KMR is a kitten milk replacer and Esbilac a milk replacer for puppies. KMR is higher in protein than Esbilac, while Esbilac is higher in fat and lower in carbohydrates. MultiMilk or Milk Matrix mixed with either of these increases the fat and protein content of the prepared feed. Heavy cream (36% milk fat and no carbohydrates) can also be used to increase the fat content of prepared Esbilac or KMR formulas. (B338.1.w1)
      • Zoologic Milk Matrix 30/55 is the same as MultiMilk. (B468.8.w8f, D252.w8)

Feeding quantity

  • Stomach capacity: The maximum amount (volume) that can be given at any one time is determined by the stomach capacity. This is 100 - 125 mL per kg bodyweight (1 mL per 10 g bodyweight). (B338.1.w1)
    • For a 30 g neonate, this is 3.0 - 3.75 mL per feed. (B338.1.w1)
  • Energy requirement:
    • This is approximately 2 x (70 x (bodyweight kg)0.75). For a 30 g neonate this would be 10.1 kcal per day. (B338.1.w1)
      • i.e. 2 x basal metabolic rate - see Food and Feeding for Mammals - Convalescent diets / Nutritional support
      • If the formula contains 2.01 kcal/mL, then (10.1/2.01) 5.02 mL (5 mL) per day would be needed for a 30 g neonate. (B338.1.w1) This would therefore need to be divided, giving 2.5 mL per feed at each of two feeds. (B338.1.w1)
    • An alternative calculation, based on daily milk energy intake in nursing infants at the time of peak lactation is 200-250 x weight (kg) 0.83. (P19.1.w5, P3.1987.w3)
  • Note: the amount to be fed should be re-calculated, based on the infant's bodyweight, every 2 - 3 days. (B338.1.w1)
  • Pre-calculation: It is useful to construct a chart, based on the energy content of your usual milk replacer, showing, for a range of weights (e.g. every 5 g from 25 g to 100g or higher), the daily kcal requirements, the volume of formula needed daily based on that, and how much formula should be fed per feed, depending on whether two, three or four feeds are given per 24 hours. (B338.1.w1)
  • Feed rabbit kits 10 mL once or twice a day until three weeks old. (B618.21.w1)

Feeding frequency

  • Usually 2-4 feeds a day are given.
  • Neonate rabbits need three feeds per day. (B602.13.w13)
  • Leverets: Start with 1 - 5 mL per feed in very young leverets, feeding three to six times a day. The volume given per feed increases gradually to 20 - 40 mL; maximum intake per day will be about 100 mL at 2- 3 weeks of age, and intake then reduces so only one feed a day is being given by weaning at 4-6 weeks. (B284.10.w10)
  • In general, suckling once a day appears to be normal for wild hare and rabbit species. However, more frequent nursing has been observed, e.g. in Lepus europaeus - Brown hare kept in cages, and in closely observed domestic rabbits in large indoor ground pens. (J46.191.w1, Th17)

Feeding method

  • Use a syringe or a bottle and teat. (B284.10.w10)
  • Note that if a syringe is used the sucking reflex may be lost and reverting to a bottle is not possible. (B601.1.w1)
  • If using a Catac bottle, the carer's thumb over the open end of the bottle controls the force required to suck the milk. (V.w5)

Weighing and Records

  • The individual's weight must be recorded regularly and accurately to allow objective monitoring of growth; weight gain should be steady, and if it isn't, this may be an early warning sign of problems such as digestive disturbance, inhalation pneumonia, septicaemia or coccidiosis. (B284.10.w10)
  • Regular weighing is also needed to calculate the amount to be fed. (B338.1.w1)
  • In general, a steady weight gain should be sought. Occasional lack of weight gain for 24 - 48 hours may occur; longer lack of gain is abnormal. (B338.1.w1)
    • If weight gain is inadequate, recalculate the caloric requirements, check the infant's general health, and if problems with weight gain recur, consider changing to a different milk replacement formula for future rearing. (B338.1.w1)
  • Also note body condition, which should be kept good or average. (B338.1.w1)


  • Domestic rabbit kits should be handled regularly and frequently once they start moving around, to improve their tameness and make them better pets. (B338.1.w1)
  • Wild species have a strong flight instinct. Minimise handling and taming of free-living rabbits and hares pre-release.
  • When catching and handling is necessary (for feeding of treatment), use gentle, deliberate movements and avoid chasing the animal. (B338.1.w1)
  • Covering the youngster with a lightweight cloth may reduce stress. (B338.1.w1)
  • Capture may be easier if the light level is lowered. (B338.1.w1)
  • Some rehabilitators consider that handling the neonates initially is important so that they become familiar with their carer, and that this reduces stress. (N35.11.w1)

Suckling rabbits, weaning and the gastrointestinal tract

  • Suckling rabbits have few microbes in the stomach or intestine; normally, their gastro-intestinal tract contains an antimicrobial fatty acid known as "milk oil" or "rabbit stomach oil", produced by an enzymatic reaction in the stomach from a substrate in the rabbit doe's milk, which provides a degree of protection against enteric infections. This protection is absent in rabbits being hand-reared and drinking substitute milks. n-decanoic and n-octanoic acids are the most active parts of this "milk oil". (B187.16.w16, B284.10.w10, J493.100.w1)
  • In the newborn rabbit, the gastric pH is 5.0 - 6.5. (B604.2.w2) Until the rabbit is three weeks old, the stomach contains octanoic and decanoic fatty acids; these keep the microbial population low despite the favourable pH for microbial survival.
  • Rabbits start eating solid food at 16-18 days old. (B604.2.w2)
  • From weaning onwards, the stomach has pH 1.0 - 2.0; this keeps the stomach and small intestine practically free of resident bacterial. The large intestine is soon colonised by facultative anaerobes (streptococci), then by strict anaerobes, particularly Bacteroides (gram-negative) but also smaller numbers of spore-forming species such as Endosporus, Acuformis, Clostridium and E coli. Clostridia and coliform bactera can proliferate and produce enterotoxins if the gut contents reaching the caecum are high in soluble carbohydrate. (B604.2.w2)
  • Development of the normal gut flora is extremely important for weanling lagomorphs. This can be encouraged by use of caecotrophs from healthy adult lagomorphs (this can be from domestic rabbits even if a wild lagomorph is being reared). (B284.10.w10, B338.1.w1, B601.1.w1, N35.11.w2)
    • Caecotrophs can be offered to the infant to eat, or mixed with milk formula and given during feeding. (B284.10.w10, B338.1.w1, B601.1.w1, N35.11.w2)
    • Caecotrophs should be given before the infant starts to be given solid food. (B338.1.w1, N35.11.w2)
    • Note: Active yoghurt (containing Lactobacilus acidophilus) (N35.1.w1) or probiotics (B600.3.w3, B606.6.w6, J417.12.w1) have been used with the aim of promoting a healthy gut microflora and avoiding overgrowth of pathogenic bacteria. These may be beneficial and are useful if caecotrophs are not available, but caecotrophs provide a much more normal gut flora for lagomorphs. (B600.3.w3, B284.10.w10)


  • The main, and often fatal, problems are Aspiration Pneumonia following inhalation of milk formula, and diarrhoea due to failure to develop the proper gut flora, followed by overgrowth of pathogenic bacteria causing diarrhoea. (B284.10.w10, B601.1.w1, W730.Dec08.w1) See:
  • Feeding by syringe allows control of the rate of milk intake, which may reduce the risk of aspiration pneumonia. (B284.10.w10)
    • Alternatively, it has been suggested that feeding by teat and nursing bottle may reduce this risk. (B601.1.w1, B606.6.w6)
  • Maintaining sterile feeding equipment reduces the risk of introducing pathogenic bacteria. (B284.10.w10, B600.3.w3)
    • Equipment can be cleaned in hot soapy water then rinsed well. Dilute bleach can be used for disinfecting feeding equipment - rinse well then air dry. Note this shortens the life of rubber plungers on syringes. (B338.1.w1)
  • Feeding caecotrophs from a healthy adult rabbit encourages development of the normal gut flora. (B284.10.w10, B338.1.w1, B601.1.w1, N35.11.w2)
Wild lagomorphs - additional considerations
  • Note: lagomorphs leave their young alone for much of the day. Healthy leverets are normally left alone in areas of grassland during the day (normal behaviour). Members of the public may find such a leveret and mistakenly assume that it has been abandoned by its parents and is in need of care. Where possible, the public should be educated that this is normal behaviour and such youngsters should be left alone unless they are obviously sick, injured or in immediate danger. (W729.Dec08.w2, V.w145)
  • The general health status of the infant should be checked when it is first presented. In particular, check it is not chilled (Chilling - Hypothermia) or dehydrated (skin pinched up should spring back quickly, the eyes should not be sunken) - see the "Assessment, initial care and stabilisation" section of the general lagomorph hand-rearing information above. 

When presented with a young lagomorph of unknown species, it is important to be able to tell the difference between young typical rabbits and young hares (leverets). (B284.10.w10, N35.12.w1)

  • Typical rabbits (including Oryctolagus cuniculus - European rabbit and most Sylvilagus spp.) are altricial, born blind, naked and helpless, and are initially in a burrow or shaped nest (depending on species). Juvenile rabbits found fully furred above ground are probably weaned and eating solid food such as grass, although they may be the same size as a very young, still suckling, leveret. (B284.10.w10, B338.1.w1, J82.16.w2)
  • Leverets (Lepus spp., including jackrabbits) are precocial; they are born fully furred, have their eyes open, are mobile from a few minutes after birth, and are left above ground. Leverets which allow themselves to be picked up are probably very young, still suckling and will need to be hand-reared and bottle fed. (B284.10.w10, J82.16.w2, N35.12.w1)
    • Note: a newborn leveret, still fully dependent on milk, may appear similar in size and general appearance to a just-weaned rabbit. (B284.10.w10, N35.12.w1)
  • Some species (Sylvilagus brasiliensis - Tapeti, Sylvilagus aquaticus - Swamp rabbit, Sylvilagus palustris - Marsh rabbit and Romerolagus diazi - Volcano rabbit) show an intermediate pattern, with young born better developed than the typical rabbits, but less so than the Lepus spp.. (J82.16.w1, J82.16.w2)
Additional hand-rearing information

The following information is available:

Brachylagus idahoensis - Pygmy rabbit

  • Kits have been hand-reared from about one week old or older (if abandoned, or if sick kits or dead kits were seen, indicating a problem).
  • Kits are housed in a nest box containing pine shavings, placed inside a crate. 
  • Kits are weighed daily to monitor progress for the first 2 - 3 weeks, then weekly.
  • Kits are fed a kitten milk replacer such as KMR. 
  • Feeding is carried out using a 1 mL syringe with a butterfly catheter, cut short as a nipple. 
  • Each kit is given its own towel for handling; handling is done with the towel to support the kit's legs, reducing the risk of leg injury, and to decrease stress. 
  • As a preventative measure against coccidial infections, a coccidiostat (ponazuril - Marquis 0.02 mL) is given orally daily for three days, also ceftiofur (Excenel, Pfizer) 0.01 mL subcutaneously daily for three days. (V.w134)
  • Once they are old enough to start eating solid food, a large amount of greens (e.g. chicory, parsley, clover, dandelion, lettuce), sagebrush, hay and a small bowl of pellets is provided daily, also Critical Care (Vetark Professional) (3 mL at least twice daily and up to six times daily if not eating or if losing weight) and Nutri-Cal (Evsco) (at least 1 mL twice daily and up to six times daily if not eating or if losing weight).
  • For sick kits, pine shavings are changed daily and any stools are removed between feeds.
  • If rearing healthy and sick kits, care for healthy kits first.
  • Wear gloves when handling sick kits and change gloves between kits.
  • A probiotic is given, 0.3 - 0.4 mL daily on greens to pregnant and lactating females, 0.1 mL orally per kit for the first two weeks after emergence from the burrow and additionally if they become ill, to boost beneficial gut microorganisms.

Ochotona princeps - American pika

  • At Denver Zoological Gardens, hand-rearing was attempted with a baby Ochotona princeps - American pika less than a week old. However, even the smallest available nipple was too large and the infant (which was cold and with a full bladder when found) died before tube-feeding could be started. (J23.15.w6)
  • Data from captive pikas showed that females nursed the young every two hours (very different from rabbits and hares) in the first week, and licked the young vigorously while they nursed. Visits to the nest became less frequent from even the second week and they visited the nest only infrequently in the third and fourth week; the young approach the female and tried to suckle starting at about 15 - 17 days. Intake of solid food started at one week and drinking of water started at 13 - 19 days (the same time as the mother was starting to avoid being suckled). Young pikas were lightly furred at birth and fully furred by two weeks old. Their ears opened at about 5 - 6 days old and the eyes at about 8 - 9 days. they started moving out of the nest from about one week old. (J334.32.w1)
Release of hand-reared lagomorphs

Note: If a hand-reared lagomorph is to be kept rather than released, then they should be handled frequently from an early age (once they leave the nest). (B284.10.w10)

  • If hand-reared young are to be released, handling should be minimised, particularly for weaned youngsters. (B284.10.w10)
  • Some rehabilitators use a hands-on (habituation) approach to hand-rearing rather than a minimal contact approach. If the juveniles are habituated to a single individual, they remain wary of other humans, therefore this should not cause problems for appropriate behaviour avoiding humans after release. (N35.11.w1)
    • It has been shown experimentally in domestic rabbits that rabbits are able to distinguish between individual humans, even when they are quite similar in size, hair colour, clothing etc. (J495.50.w1)
  • For Oryctolagus cuniculus - European rabbit, once they are weaned and vaccinated against myxomatosis (at six weeks old) and viral haemorrhagic diseases (at 10 weeks old, or preferably (V.w44) 12 weeks old), the litter can be released by placing the box, containing the nest and young rabbit(s), in a suitable site and leaving the box open - this gives the rabbit(s) somewhere to return to initially after release. (B284.10.w10)
Ferret Consideration Handrearing of neonatal ferret kits is very difficult. (B338.26.w26, B602.1.w1)
  • Hand-rearing may be needed if the jill totally rejects the kits, or does not produce (or stops producing) milk due to illness, and there is no other jill available with which the kits can be fostered. (B338.26.w26)

Further information on hand-rearing domestic ferrets is provided in: Hand-Rearing Ferrets (Mustela putorius furo)

Bonobo Considerations

Orphaned bonobos need close physical contact. Click here for full page view with caption Bottle feeding an infant bonobo. Click here for full page view with caption Bottle feeding and infant bonobo through wire mesh. Click here for full page view with caption Infant bonobo holding rope. Click here for full-page view with caption Infant bonobo climbing. Click here for full-page view with caption

"The goal of hand-rearing is to return that individual to the group with the self-confidence, physical abilities, communication skills, and social skills necessary to be a well-adjusted participant in the group and ultimately a contributing member of the species." (D386.3.1.w3a) 
  • If a decision is made that hand-rearing is needed (due to medical problems of the infant, or serious/persistent maternal neglect) then the plan for not only the rearing but also the infant's re-socialisation into the group should have been produced in advance. (D386.3.1.w3a)
  • If hand-rearing is to be carried out, both the physical and the psychological/social needs of the infant must be met. N.B. it is important to remember that learning and development start from day one, and that the physical development, psychological development and social development affect each other and cannot each be considered in isolation. (D386.3.1.w3a)
  • Data from Lola ya Bonobo, based on both behavioural and cortisol measurements, indicate that the bonobos hand-reared there are not psychologically disadvantaged compared to mother-reared bonobos at Lola ya Bonobo (infants born to mothers in the sanctuary) or to bonobos parent-reared in Western zoos. They have similar average salivary cortisol levels to parent-reared individuals at the sanctuary, and similar cognitive abilities to parent-reared individuals at the sanctuary or in a zoo (Leipzig Zoo). The same were noted for infant Pan troglodytes - Chimpanzees reared in an African sanctuary. However, it must be noted that the orphans at Lola ya Bonobo (and the orphaned chimpanzees in the Tchimpounga sanctuary) have been parent-reared for varying lengths of time, but probably usually two to three years, before their mothers were killed, and therefore have had a considerable amount of time in a normal social environment before being hand-reared. (J473.6.w1)
    • An additional study was carried out on infant Pan troglodytes - Chimpanzees which found a near-absence of abnormal behaviours (little rocking, almost no coprophagy and no faeces-smearing) and similar or higher levels of species-typical behaviours (grooming, eating) in the sanctuary-reared orphans compared to zoo-housed chimpanzees in a highly-enriched environment. (J473.6.w1)
Decision making regarding hand-rearing

Hand-rearing should never be the preferred choice but may be necessary due to medical problems with the infant, maternal neglect, or if an infant is orphaned. (D386.3.1.w3a, W758.Aug2011.w1)

  • An infant should not be removed for hand-rearing simply because the mother has a history of neglecting one or more previous infants. For example, a mother may rear her first infant, reject her second but then successfully raise her third offspring. (D386.3.1.w3a)
  • A female should be considered to be an unsuitable mother only if she is consistently harmful to her infants. (D386.3.1.w3a)
  • Initial assessment of an infant great ape once it is taken for hand-rearing should include: (B23.50.w50)
    • Airway, adequate ventilation, any bleeding (this should be controlled).
    • Assess for hypothermia and hypoglycaemia.
    • General examination including assessment of maturity, birth trauma, petechiae or jaundice (either of which may indicate sepsis).
    • Assess the mucous membranes for jaundice or cyanosis
    • Palpate the cranium; check for bulging fontanelles and for fractures.
    • Check for any congenital defects (e.g. atresia ani, nasal atresia or other craniofacial defects, hypospadias, umbilical hernia, inguinal hernia).
    • Auscultate the chest bilaterally for heart and respiratory sounds.
    • Palpate the abdomen to check for masses, organomegally, distension.
      • .B. the testes are likely to be inguinal in the newborn great ape.
    • Assess neurologically for alertness, muscle tone, sucking and grasping reflexes and cry-response. Check responses are bilaterally symmetrical.



  • Accurate records should be kept including: (D386.3.1.w3a)
    • Details of the milk replacement formula used, the actual composition of formula provided to the infant and the amounts taken by the infant. (D386.3.1.w3a)
    • The production of faeces, including amount and consistency. (D386.3.1.w3a)
    • The weight of the infant (daily). (B23.50.w50, D386.3.1.w3a) 
      • Expect weight loss in the first week, then daily gain; steady progress, rather than the absolute rate of weight gain, is most important. If weight gain stops or weight is lost, for more than 2-3 days, this suggests the possibility of inadequate nutrition, or illness. (B23.50.w50)
      • N.B. the weight is used to calculate the quantity of milk replacement formula to give the infant. (D386.3.1.w3a)
    • The activity level of the infant, its general development, responses to specific stimuli. (D386.3.1.w3a)
    • Any veterinary care given. (D386.3.1.w3a)
    • Notes on the hand-rearing method used. (D386.3.1.w3a)
Physical needs
Initial stabilisation
  • Initial care of a newborn great ape if hand-rearing is required includes: (B23.50.w50)
    • Umbilical cord: clean, disinfect, clamp, cut and tie or clip.
    • Washing of the whole infant using warm water, dried thoroughly and placed in an incubator (controlled temperature, initially 90 - 95 F).
    • Obtain vascular access if needed.
    • Consider giving 5% glucose by intravenous or intraperitoneal injection or by nasogastric tube.


  • Initially maintain in an incubator/isolette set at 30 C (85 F) until the infant can maintain its body temperature (rectal temperature 36-37 C, 98 F). Then decrease the temperature by 1 C (2 F) per day to reach a room temperature  of 24-26 C 75-78 F. (B338.18.w18)
  • By 7-14 days an infant great apes should be able to maintain its body temperature when outside the incubator/isolette. It can then be moved into a 0.6 x 1 m box (2 x 3 ft) with a viewing window, with blankets for warmth. (B338.18.w18)
  • Usually, nappies (diapers) will be used to facilitate hygiene of the infant great ape. (B23.50.w50)
  • These should be changed frequently (several times a day) to minimise the risks of skin irritation caused by contact with urine and faeces. (B23.50.w50)
  • Zinc oxide-based emollient creams or drying agents such as talc may assist with skin care but are not a substitute for good care. (B23.50.w50)
  • Do not feed a hypothermic infant orally until it has been warmed to normal body temperature. (D386.3.1.w3a)
  • Give a neonatal ape water or 5% glucose for the first 24 hours of hand-rearing to minimise risks of aspiration while the infant coordinates suckling from a bottle. If the infant feeds normally, milk formula can then be given. (B23.50.w50)

Milk replacers

  • Bonobos have been hand-reared successfully using human infant milk formulas such as Enfamil, Similac, and SMA.  (D386.3.1.w3a)
  • Initially avoid formulas with iron, as these may stimulate bacterial growth. (B23.50.w50)

Calculation of volume:

  • Initially give 5 - 10 mL per feed, increasing to ad libitum feeding. (B23.50.w50)

There are two basic methods for determining the approximate amount of milk replacer needed.

  • 1) Feed about 20% of the infant's body weight of formula daily (divided over the number of feeds), using a 1:1 mix of formula to water. Increase the amount if the infant is losing weight by:  (D386.3.1.w3a)
    • a) increase the volume fed (if the infant will take more); or  (D386.3.1.w3a)
    • b) increase the strength of the formula mix to two parts formula to one part water. Note: the infant may develop diarrhoea with this change, and any diarrhoea must be controlled quickly.  (D386.3.1.w3a)
  • 2) Calculate the daily energy needs of the infant: 120-150 Kcal per kg body weight per 24 hours, then calculate the quantity of formula required to meet those needs, and give this divided over the total number of feeds. (D386.3.1.w3a)
    • e.g. for an infant bonobo weighing 2.0 kg, the bonobo would need at least 2.0 x 120 = 240 Kcal/day. SMA contains 20 kCal per 30 mL (when made up as directed), so 360 mL of SMA would be needed daily. If this is to be given in 12 feeds (i.e. feeding every two hours throughout the 24 hours), the infant would need to take 30 mL per feed.  (D386.3.1.w3a)
    • Calculate for 100 -120 kcal/kg per day (general great ape information). (B23.50.w50)

Frequency of feeding

  • Initially every 1-2 hours. (B23.50.w50)
  • Initially feed every two to three hours throughout the day and night.  (D386.3.1.w3a)
  • If the infant's general health is good and it is willing to take a larger quantity per feed, then it is possible to reduce the number of feeds (no more than a reduction of one feed a day, per week), while increasing the volume given per feed to keep the total volume the same. (D386.3.1.w3a)
  • From about two weeks of age, feeding of great ape infants can be carried out between about 8 am and 2 am, with a six-hour overnight break. By this stage, they can be fed up to 30 minutes earlier than scheduled if awake and hungry, or up to 30 minutes later if they are sleeping at the designated feeding time. (B338.18.w18)
  • From about 4-5 weeks of age, feeds can be given every four hours, with six feeds a day. (B338.18.w18)
  • From about two months of age, feeds can be given five times a day from 9am - 11 pm. (B338.18.w18)
  • From four months, feeds can be given four times a day. (B338.18.w18)
  • From six months, feeds can be given twice daily. (B338.18.w18)

Method of feeding

  • Handle as a human infant. Allow the infant to rest in the cradle of the arm at about a 45 degree angle. (B338.18.w18)
  • Gently place the nipple into the infant great ape's mouth, but do not force it. (B338.18.w18)
  • If the nipple is not initially accepted, rub the infant's chin. (B338.18.w18)
  • Expect several short sucking bouts, each of only a few seconds, during the first week. Note: allow rest periods of a few minutes between sucking bouts while the infant develops its suck reflex.  (B338.18.w18)
  • If a great ape infant is unable to suckle properly, feeds can be given by gavage:
    • Use a soft 12-French polyethylene nasogastric tube.
    • Secure the tube in place using tape.
    • Check for residual fluid from the previous feed before giving the next feed
    • Give 2-3 mL per feed initially, every two hours.
    • If there is more than 1-2 mL of residual fluid in the stomach, the next feed should not be given and the cause of the retention should be investigated. 


Feeding utensils

  • The size of the nipple aperture should be chosen to allow easy flow of milk without milk flow being so fast that it cannot be readily swallowed. (B23.50.w50)

Introduction of solid food, and weaning

  • Start providing pieces of solid foods for the infant to manipulate, smell and taste from four months (even though it is unlikely to actually eat any solids at this age). (D386.3.1.w3a)
  • Provide food items in a size which is easy for the infant to pick up. (D386.3.1.w3a)
  • Make sure all items are of a size such that the infant cannot choke if it does eat the food. (D386.3.1.w3a)
  • Root vegetables such as carrots and yams may be steamed (to soften them) initially. (D386.3.1.w3a)
  • Once the infant has started to eat solid food and is eating larger amounts, the volume of formula given can be reduced. (D386.3.1.w3a)
  • The weaning process is dependent on the weight gain, food consumption and general health of the infant. (D386.3.1.w3a)
  • Gradually add in other items of the adult diet, including primate biscuits and children's chewable vitamin tablets by 10-12 months; by this time the infant will be on about 360 mL milk twice daily.  (D386.3.1.w3a)
Physical stimulation


  • From a very early age it is important that the bonobo infant is exposed to a variety of stimuli and is given opportunities to develop its motor skills. (D386.3.1.w3a)
  • The infant should not be left lying in one position for long periods. (D386.3.1.w3a)
  • Very young infants preferably should be put into a carrier strapped to the caregiver and carried around while the caregiver works in the nursery area, providing essential tactile stimuli and movement. (D386.3.1.w3a)
  • A fake-fur vest can be worn by the caretaker; the infant can grip this and develop its gripping muscles. (D386.3.1.w3a)
  •  Opportunities should be given for the infant to see, feel, small and taste.
  • The infant should be helped to move or climb.
  • Audio tapes of bonobo vocalisations may be beneficial stimuli. (D386.3.1.w3a)
  • Grooming of the infant by the keeper is beneficial. (D386.3.1.w3a)
  • Mirrors are also a beneficial stimulus. (D386.3.1.w3a)
  • While an infant great ape is in an incubator, colourful objects can be suspended where the infant can see them. (B23.50.w50)
Psychological and Social needs
"Prolonged isolation could result in social retardation, health problems, inability to raise infants and aberrant behavior." (D386.3.1.w3a)
  • The rearing environment should meet and preferably exceed the infant's developmental needs. (D386.3.1.w3a)
  • There should be a variety of visual, tactile and auditory experiences present, and these should vary periodically. (D386.3.1.w3a)
  • During routine care-giving (feeding, changing nappies (diapers), the infant great ape should be cuddled and spoken to. (B23.50.w50)
  • A sense of security is very important to the infant. (D386.3.1.w3a)
    • When new stimuli or experiences are encountered, a familiar blanket, toy, or individual can provide the security required to reduce fear. (D386.3.1.w3a)
    • The caretaker is very important in providing comfort and security, from which the infant can gain self-confidence and learn to be independent. (D386.3.1.w3a)
    • Tactile stimuli of touching, holding and being held are essential for primates.  (D386.3.1.w3a)
  • While the potential for imprinting cannot be ignored, it is considered that this can be offset by ensuring the infant is socialised to conspecifics as early as possible. Caretaker-infant contact and interaction is critical for the infant's well-being and development. (D386.3.1.w3a)
    • Mimicry, by the caretaker, of normal (species-specific) facial expressions and vocalizations may be advantageous, as well as exposure to normal conspecifics (adults). (B23.50.w50)
  • The youngster should have social interaction with others of the same age (or even with younger infants); this may have significant effects on development of appropriate sexual and parental behaviours later. (D386.3.1.w3a)
  • If possible, the bonobo should be reared together with another bonobo infant, or if this is not possible, with another primate. It is important to remember that species-typical experience is needed if the infant is to develop species-typical behaviour. It may be best to move one infant so that it can be with another infant in a different institution.  (D386.3.1.w3a)
    • When two infants are introduced to each other the caretaker should closely supervise the infants and provide appropriate guidance and discipline as necessary to ensure security and comfort are provided and to avoid serious injury. (D386.3.1.w3a)
  • Alternatively, the infant can be exposed to its natal social group: consider setting up the hand-rearing unit within the main bonobo facility. If the infant has seen, heard and smelled the rest of the group and experienced their social behaviour, then integration back into the group may be less stressful, and the infant will have a better understanding of the social environment and how to participate in it, including understanding social cues for affliliation and play. Without this understanding, it is likely to focus on protecting itself and avoiding potential conflicts, which may have major repercussions for its integration into the group. (D386.3.1.w3a)
  • Initial introductions to bonobos in the group should be to individuals which have shown active, non-aggressive interest when given visual contact with the bonobo. The infant must have sufficient locomotor skills to be able to move away from a real or perceived threat, and the introduction must be carefully planned and constantly monitored. Usually an easygoing experienced mother is chosen for the first introductions and for the infant to bond with; this should be an individual with sufficient social standing to protect the infant from any aggression. (D386.3.1.w3a)
  • Note: 
    • During the introductory period, a "creep" cage should be provided into which the infant can retreat while other bonobos cannot enter. This lets the infant avoid conflicts, for example at times of increased tension. (D386.3.1.w3a)
    • The group into which the infant is being introduced should be well-established and stable, providing a relatively low-stress social environment for the infant. (D386.3.1.w3a)
    • If the introductory process is harming the infant either physically or psychologically, then it must stop until an alternative method of introduction is possible, or until the hand-reared bonobo is older and larger. If just one individual is being abusive to the infant, it may be possible to remove that bonobo for a short time until the infant is integrated with the rest of the group and other group members will protect it when the abusive individual is re-introduced. However, removal of an individual for a longer time should be avoided as this may disturb the dynamics of the group. (D386.3.1.w3a)
  • After a few weeks of daily interaction, the infant should start choosing to remain with the other bonobos rather than returning to its caretaker. Usually, the other bonobos will help the infant to move with the group, and older males often protect the infant. (D386.3.1.w3a)

Associated techniques linked from Wildpro




Return to top of page

Authors & Referees


Debra Bourne MA VetMB PhD MRCVS (V.w5)


Tiffany Blackett BVetMed MRCVS (V.w44); Gail Hedberg (V.w106); Mike Jordan (V.w30); Chris Lasher (V.w110)

Return to top of page