TECHNIQUE

Hand-rearing Polar Bears  (Disease Investigation & Management - Treatment and Care)

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Summary Information
Type of technique Health & Management / Disease Investigation & Management / Techniques:
Synonyms and Keywords Hand-rearing Ursus maritimus - Polar bear
Description
Initial Care
  • Transport the cub in a heated insulated box lined with a towel and provided with a safe heat source. (B338.24.w24)
    • Microwaveable heat pads can be used which retain heat for four to six hours. (V.w106)
    • Latex examination gloves filled with warm water can be placed next to the cub(s) to provide an initial heat source, but will only remain properly warm for about 30 minutes. (B338.24.w24, V.w106)
  • Check the cub's temperature using a paediatric digital rectal thermometer. (B338.24.w24)
  • Place in an incubator set at 30 - 32 C / 86 - 88 F and surround the cub with bags of warm fluid: latex examination gloves filled with water, or 250 mL intravenous fluid bags. (B338.24.w24)
    • As the bags or gloves of fluid cool down, replace them with fresh warm bags. (B338.24.w24)
    • Microwavable heat pads can be used which retain heat for four to six hours. (V.w106)
  • Apply 0.5% chlorhexidine solution (use sterile water to dilute 2% solution to 0.5%) to the umbilicus. (B338.24.w24)
    • The umbilicus should dry and disappear by the time the cub is about 48 hours old. (B338.24.w24)
    • Tincture of iodine has been used on the umbilicus. (J2.30.w3)
      • Using iodine solution on the umbilicus risks chemically burning the end of the stump and trapping bacteria within the stump. (B338.24.w24)
  • For cubs which have not nursed from their mother [and therefore will not have taken in maternal antibodies], give polar bear serum:
    • Recent recommendations, based on data from domestic cats (J4.219.w6), are to give 7.5 to 15 mL per 100 g bodyweight, parenterally (e.g. subcutaneously). (V.w106) Earlier recommendations or practices recorded include: 
      • Give polar bear serum, 6.6 - 11 mL/kg (3 - 5 mL per pound) bodyweight in two doses five to 10 days apart. [2006] (D251.8.w8)
      • Give serum, divided intravenously and orally: 22.0 mL/kg. [2002](B338.24.w24)
      • Cubs were given 5 mL serum (previously collected from their mother and stored frozen) twice (two consecutive days). [1999] (J2.30.w3)
      • Cubs were given polar bear serum: 5.0 ml orally, 2.5 ml subcutaneously and 2.0 ml intraperitoneally. [1974](J23.14.w3)
  • At Topeka Zoo, cubs were given iron dextran, 5 mg/kg at birth, one month and three months. (J23.14.w3)
  • The patent umbilicus of one cub was treated by application of a silver nitrate stick initially, and the following day by application of tincture of iodine; this was applied to the navels of both cubs for 11 days to prevent infection. (J23.11.w3)
  • Chloromycetin was given daily as a preventative treatment to avoid infection. Bacitracin ointment was applied to the cub's noses when they became raw due to rooting in the incubator, and also to the anal area after this became raw. Injections of vitamins (0.2 mL per cub, of a mixture of vitamin A 500,000 units/mL, D2 (vitamin D) 75,000 units/mL, vitamin E 50 units/mL in a water-emulsifiable base every two weeks, and 1 mL iron dextran (100 mg iron/mL). (J23.11.w3)
General Care (including warmth and hygiene)
  • Initially, cubs should be kept in an incubator set at 30 - 32 C / 86 - 88 F. (B338.24.w24)
    • Young cubs must be kept warm. (B338.24.w24)
    • Once cubs are fully furred they are more tolerant of lower temperatures. The temperature of the incubator can be reduced by a few degrees per day from about 3-4 weeks onwards, until it reaches room temperature. (B338.24.w24)
    • By about 7-8 weeks the preferred ambient temperature for polar bear cubs is lower than that for humans. (B338.24.w24)
    • Note: Hand-reared cubs at Denver Zoological Gardens were observed to have poor thermoregulation in their first two weeks, preferring the incubator at 29-31 C. At about two weeks old, coinciding with the development of more hair, thermoregulation appeared to improve and cubs preferred an incubator temperature of 18 C or lower, appearing uncomfortable (crying, squirming and not sleeping) when maintained at higher temperatures. (J23.39.w1)
  • Litter mates may be kept together; it may be necessary to separate them if sucking on the other cub's genitals becomes a problem. (B338.24.w24)
  • Keep incubators clean; have more than one incubator to allow a rapid transfer from a soiled to a clean incubator. (B338.24.w24)
    • Always keep the cub in a clean environment; it should never be exposed to a faecally-soiled environment. (B338.24.w24)
  • The incubator should be padded to reduce snout damage when the cub "roots" at the substrate. The perimeter of the incubator should be lined with soft guards. (B338.24.w24)
    • Cotton stockingette filled with rolled cotton or styrofoam bean-bag beads can be used. (B338.24.w24)
    • Polyester fleece can be used; take care that fibres are not ingested as these may cause intestinal obstruction. (B338.24.w24)
  • Cubs were placed each in a human Isolette (isolating incubator), at 32 C and 50% humidity. (J23.14.w3)
    • For the first two weeks only two people were allowed into the room. The handlers scrubbed with surgical soap before handling the cubs. (J23.14.w3)
    • The Isolettes were cleaned and disinfected daily. Each cub was kept on a Decubicare pad [these are designed to transmit pressure evenly, allow circulation and permit drainage] and the pad changed whenever it became soiled. (J23.14.w3)
    • The temperature of the Isolettes was gradually reduced over a month to 22 C. (J23.14.w3)
  • The cub was kept in an isolette at 28 C (82 F) initially. In the seventh week the temperature started to be reduced, by 2 C every other day, down to room temperature. Once at room temperature the cub was moved to a hardboard-lined playpen. (J23.11.w4)
  • Initially in an infant incubator at 31 C (88 F) and 40% humidity. Temperature reduced gradually, reaching 24.5 C (74 F) by 2.5 weeks and room temperature (maintained at 21 C (70 F) by three weeks; the cubs became restless if the room temperature rose above this level. The male was removed into a large box at 2.5 weeks (the incubator was no longer large enough for both cubs) and from three weeks they were housed in an infant play-pen lined with rigid sheets of vinyl. The floor of the play-pen was covered with a play-pen pad then nylon carpet to give a firm grip for the cubs. (J23.11.w3)
  • To ensure fluid balance, subcutaneous fluids can be given for the first three days. (V.w106)
Milk Replacer
  • Note: Information on polar bear milk composition is available in: Polar bear Ursus maritimus - Life Stages (Literature Reports) - Lactation
  • Milks used have included Esbilac, Esbilac mixed with cream or with half-and-half, or Esbilac mixed with other milk replacers such as Multi-Milk. (D251.8.w8)
    • Addition of lactase enzyme has been used by some institutions, since polar bear milk is low in lactose. (D251.8.w8)
    • Commonly, paediatric vitamins are added; this may not be necessary if the milk replacer used is nutritionally complete. (D251.8.w8)
    • Cod liver oil has been added, but cubs have been raised successfully without this. (D251.8.w8)
  • 1) Esbilac Powder or Milk Matrix 33/40. Esbilac Powder is made up with sterile water at a 1:3 powder:water ratio for the first eight days, 1:2 ratio days 9-15, 1:1.5 days 16-29, 1:1 days 30 to weaning. (B338.24.w24)
    • Add 0.5 mL ABDEC (paediatric liquid oral vitamin preparation) per 100 mL prepared formula. (B338.24.w24)
  • 2) Initially: Esbilac made up 1 part powder to two parts sterilised water (60% of formula) plus cow's cream with one teaspoon cod liver oil (40% of formula), plus 0.3 ml ADIDEC multivitamins daily. (J23.14.w3)
    • From two weeks: Esbilac made up 1 part powder to two parts sterilised water (two parts of formula) to one part light cream, plus, per 100 ml, one teaspoon cod liver oil, 1/2 teaspoon NeoCalglucon, 300 mg Inositol, 0.5 ml Polyvisol vitamins, 1.5 drops Aqua-Sol E. (J23.14.w3)
    • Formula was fed fresh, with no more than a few hours of refrigeration, and was warmed before being given. (J23.14.w3)
  • 3) Esbilac, powder made up 1:3 with water in the first week, 1:2 in the second week, 1:1.5 in the third week, then 1:1 from the fourth week onwards. In the twelfth week, the formula was gradually replaced by canned evaporated milk. (J23.11.w4)
    • Cod liver oil was added at 5 mL per day for the first four weeks, 7.5 mL per day in the fifth and sixth weeks and 10 mL per day in weeks 9-12. (J23.11.w4)
    • ADIDEC liquid vitamins were added, one drop per day in the second week, the amount then being increased every second week by one additional drop per day, reaching six drops per day by 12 weeks.
    • Karo syrup [corn syrup - i.e. glucose syrup] was given at 1.26 mL per feed. This was considered to assist with urination and defecation. (J23.11.w4)
  • 4) For two cubs reared from about 90 days old in 2001: (D251.8.w8)
    • Days 90-100, 11.5 g Esbilac powder, 11.5 g Enfamil powder, 4 g corn oil, mixed with 73 g water;
    • Days 101-222, 13.5 g Esbilac powder, 13.5 g Enfamil powder, 4 g corn oil, mixed with 69 g water;
    • Days 222-343: 14.5 g Esbilac powder, 14.5 g Enfamil powder, 2 g corn oil, mixed with 69 g water.
  • 5) At Denver Zoological Gardens, two cubs hand-reared from a few hours old initially were fed 70% half-and-half milk and 30% powdered Esbilac reconstituted 1:1 by volume with distilled water. Each 100 mL milk was supplemented with 10 mL of cod liver oil and 0.5 mL liquid vitamin supplement. (J2.30.w3)
    • Problems with bloat in both cubs, and development of a gastric lactobezoar in one cub, led to a change with the Esbilac diluted 1:3 with water and the cod liver oil replaced by safflower oil. The gastrointestinal problems resolved, but the cubs developed rickets (see: Calcium-Vitamin D Metabolism Imbalance (with special reference to Hedgehogs, Elephants and Bears)). After this, the safflower oil (which does not contain any vitamin D3) was replaced with 5 mL cod liver oil. The final diet was 60% Esbilac, 40% half-and-half milk fortified with cod liver oil, liquid multivitamins and Neo-Calglucon (calcium gluconate). (J2.30.w3)
  • 6) At San Diego Zoo, cubs were reared from 5.5 and 7.7 kg, on a formula of equal parts Esbilac powder and Enfamil Powder (human milk replacer) mixed with water, vegetable oil and lactase. (N30.74.w1)
  • 7) Milk formula of either one part Esbilac, one part distilled water and one part half-and-half OR one part Esbilac, three parts distilled water, one part whipping cream (pretreated with lactase enzyme for 24 hours). Plus, cod liver oil 5 mL/day, increasing to 10 mL per day for older cubs, Karo syrup [corn syrup - i.e. glucose syrup] 4 mL per 100 mL formula, NeoCalglucon 2.5 mL per 100 mL formula, liquid human paediatric vitamins (e.g. Poly-vi-sol) 1 mL per day, liquid iron supplement (e.g. Fer-in-sol) three drops per 100 g formula. Initially feed diluted one part formula to three parts water, increasing to full strength over the first week. (B379.37.w37)

    (D251.8.w8)

  • Note: Recent analysis comparing the fatty acid composition of Esbilac to that of Ursus maritimus - Polar bear adipose tissue (which has similar proportions of fatty acids to polar bear milk) indicates that Esbilac has a substantially higher polyunsaturated fat content. It has been suggested that e.g. fish oil may be more suitable than whole cream or half-and-half to increase the fat content of milk replacers for rearing Ursus maritimus - Polar bear cubs. (J54.25.w2)

    • Liquid Esbilac had 24% saturated fatty acids, 26% monounsaturated and 50% polyunsaturated, compared with tissue adipose which had 30% saturated, 50% monounsaturated and only 15% polyunsaturated fatty acids. Further information is provided in the Notes section below (J54.25.w2)
Utensils
  • Human infant bottles, with various nipples, may be used. Playtex nipples may prevent chapping on the cub's nose. Nipples for premature babies, orthodontic "Nuk" nipples, elongated nipples and nipples designed for infants with cleft palates all have been used. (D251.8.w8)
    • If opening a hole in the nipple to allow milk to flow more freely, care must be taken to ensure flow is not too rapid, since formula may be aspirated. (D251.8.w8)
    • Note: Bear cubs need to suckle; if the hole in the nipple allows rapid feeding, they may still need to suckle for longer on the nipple or the carer's arm, or they will find other objects to suck on (e.g. their own footpads, other cubs' ears). (D270.VII.w7)
  • All feeding utensils were sterilised after use. (J23.14.w3)
  • Milk was fed from a glass baby feeding bottle with a regular nipple. (J23.14.w3)
    • As the cubs grew the hole was enlarged. (J23.14.w3)
  • Initially an extended rubber nipple was used (first day and a half), which could be pumped, then a premature baby nipple was used to 21 days, followed by an ordinary rubber nipple; at 52 days the hole in the nipple was made larger. (J23.11.w4)
  • Use a human premature nipple, enlarging the hole as the cub grows. A nipple designed for humans with cleft palate was found to work best for one cub. (B379.37.w37)
  • Feeding from a syringe has been used successfully starting at 90 days of age. (D251.8.w8)
  • Feeding can be carried out using a nasogastric tube (polyurethane infant feeding tube) if the cub will not suckle. (B379.37.w37)
  • Feeding can be carried out via a nasogastric tube in an ill cub; close monitoring of suture sites is important to prevent infection. (D251.8.w8, D315)
Feeding Frequency
  • Initially feed throughout the day and night, every 2-3 hours at evenly-spaced intervals. Frequency can be reduced as the cub grows, reaching 5-7 times daily by one month old, but should be dependent on the cub's health status. The number of feeds per day then gradually decreases to weaning. (D251.8.w8)
  • Initially every two hours, gradually reducing to six or seven times a day. (B379.37.w37)
  • For the first 15 days, every 2.5 hours (nine feeds per day), 16-22 days, every 3 hours (eight feeds/day), 23-29 days seven feeds/day, 30-74 days six feeds/day; 75 days four feeds per day. (B338.24.w24)
  • Every three hours from 0800 to 2300 for the first month, then six feeds daily to 56 days, then four times daily. (J23.14.w3)
  • Eight times a day (every 2.5 hours) from 0600-2300 in the first week; seven times a day from 0630-2200 in the next three weeks; six times a day, from 0630-2130 (every three hours) in weeks five to 12. (J23.11.w4)
Feeding Technique
  • Bear cubs must be fed lying on their front with the head slightly elevated holding the nipple of the bottle. A bear cub fed while upright, or lying on its back, or in a head back position, may inhale milk and this may result in aspiration pneumonia (Aspiration Pneumonia in Birds, Elephants and Bears). (B123.19.w19, D315)
  • Cubs will tend to paddle forwards at first; a rolled towel for the cub to push against while suckling may help. (D315)
Quantities
  • Limit the cub's intake: initially 28 mL/feed, days 23-29 42 mL/feed, days 30-47 56 mL/feed, days 48-50 71 mL/feed, days 51-74 85 mL/feed, days 75 to weaning, 120 mL/feed. (B338.24.w24)
  • Start at 30 mL (1 oz) per feed (at every two hours); as a guideline, give 15-25% body weight in formula daily. (B379.37.w37)
    • Changes in the amount of formula should be made gradually. (B379.37.w37)
    • The amount fed should be guided by weight changes. (B379.37.w37)
  • Feed 15-25% of body weight per day, and no more than 5% body weight in any one feeding session. The quantity given can be reduced gradually to 10-20% of body weight per day by the age of 90 days. (D251.8.w8, D315)
  • Cubs were fed "enough to show a steady weight increase. If there was no gain in weight, the quantity was increased." (J23.14.w3)
  • The cub was given 28 mL per feed in the first three weeks, 42 mL per feed in the fourth week, 56mL/feed in the 5th-7th weeks, 85 mL/feed in the 8th-11th weeks and 113 mL/feed in the 12th week. (J23.11.w4)
Toileting/Elimination
  • Bear cubs require toileting. Stimulate the bear at each feed by gently patting the perineal area with a gauze or cotton pad soaked in warm water. (B338.24.w24)
    • Have the bear in a sternal position and, using a warm, moist cotton ball, gently stroke from the belly to the anus. (D315)
      • Only slight pressure is required. (D315)
    • Preferably carry out this procedure with the cub on a disposable adsorbent pad, such as an incontinence pad, and discard this once it is soiled. (B338.24.w24, V.w106)
    • Wear latex gloves, then these can be removed quickly and the carer can move straight on to feeding the cub. (B338.24.w24, V.w106)
    • After a week, toileting is requires only twice daily. Once the cub is eating solid food, once daily is sufficient. (D315)
    • Defecation without assistance usually occurs by no later than 8-10 weeks of age. (D315)
Weighing
  • Daily, at the same time each day. (B338.24.w24, B379.37.w37D251.8.w8, J23.14.w3) 
    • After initial stabilisation, a weight gain of 30-90 g per day can be expected. (B338.24.w24)
    • Daily weights can be used to guide the amount of formula to be fed. (B379.37.w37)
    • Cubs gained weight to reach about 2.25 kg by one month and 5.25 kg by two months of age. (J23.14.w3)
    • Cubs which are mobile can be trained to enter a crate or step onto scales for weighing. (N30.74.w1)
    • Scales should be calibrated yearly. (V.w106)
Weaning 
  • Note: In the wild, polar bear cubs suckle to 2-3 years of age; it is not known at what age nursing becomes primarily a form of social bonding rather than nutritional dependence. (D251.8.w8)
  • Suggested schedule 1: Weaning from the bottle and introduction to solid foods may start as early as 60 days; it is more common to start at 70-85 days. (D251.8.w8, D315)
    • Introduction to solid foods involves addition of e.g. baby cereal, canned cat or dog food, or ground dry cat or dog food to the formula. (D251.8.w8, D315)
    • From three months, dog kibble or omnivore biscuit can be introduced, initially ground or soaked, gradually progressing to dry foods. (D251.8.w8)
    • Fish and meat have been offered from as early as 100-110 days. (D251.8.w8, D315)
    • Note: only one variable should be changed at a time, so it is possible to assess the cub's response to each change. (D251.8.w8, D315)
  • Suggested schedule 2: From 50 days, start adding to the milk of a good quality commercial canned carnivore diet (e.g. Hill's Feline Science Diet CD), in 15 g (one tablespoon) increments, to reach 120 g per day. From 75 days, cubs should be eating prepared formula (Esbilac Powder 1:1 ratio with water) and Hill's Feline Science Diet CD in a 2:1 ratio, mixed in a bowl. Gradually introduce soaked omnivore biscuit and change over to this at 80 days. (B338.24.w24)
  • Introduce water gradually in a shallow pan from about two months. (B338.24.w24)
    • Care is required; the cub tends to put its whole head into the water initially. (B338.24.w24)
  • Suggested schedule 3: Weaning can start at 10-16 weeks. Initially offer formula in a bowl, then start adding pre-cooked baby cereal (Gerber rice cereal, Fremont, MI) to this, then start to add solid food, such as Hill's Prescription diet C/D or I/D, or ZuPreem omnivore diet, soaked in formula. (B379.37.w37)
    • Wean gradually, changing only one item at a time, and expecting to wean the cub over a period of about two months. (B379.37.w37)
    • Offer water in a shallow pan to reduce the risk of cubs putting their whole head in the water. (B379.37.w37)
  • Further notes from experience with different cubs:
    • Cereal was offered when the cubs were about two months old and solid food was offered a week or two later. (J23.14.w3)
    • It was difficult to wean the cubs from the bottle to feeding from a bowl. (J23.14.w3)
    • Solid foods were added gradually and milk formula reduced. Foods included I/D, Zu/Preem Omnivore diet and whole raw apples (which were also used as toys). (J23.14.w3)
    • From day 85 to 93 days, 57 g (2 oz) pre-cooked baby cereal was added to the milk formula twice daily, then Hill's C/D was added. By 99 days the cub was onto C/D eaten from a pan. After this, Purina Dog Chow was added and gradually replaced the C/D so than the cub was on the Dog Chow alone by day 141. (J23.11.w4, J23.12.w2)
Release
  • The US Fish and Wildlife Service does not recommend the release of hand-reared 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)
    • Released cubs would probably starve or be predated by an adult polar bear. (D259.VIII.w8)
Appropriate Use (?)
  • Hand-rearing may be necessary if the dam neglects her cubs or injures them, for example by excessive grooming. (B338.24.w24)
    • The bear should surround newborn cubs with her body, keeping them warm, and should lie on her back to let them nurse. (B338.24.w24)
    • Distressed cubs initially cry (bawl) loudly and excessively. However, a weak, compromised cub, will be unable to vocalise in this way. (B338.24.w24)
    • Monitoring the den using infrared camera and/or a microphone is suggested. (B338.24.w24)
    • Maternal neglect and trauma are the two primary causes of mortality for polar bear cubs born in captivity. (B338.24.w24)
Notes
  • Recommended advance preparations include:
    • Obtain and keep in good condition at least two human infant incubators (isolettes) or equivalent, with thermostatically controlled temperature and the option to control humidity. (B338.24.w24)
    • Have various sterilised feeding bottles, nipples, surgical gowns and sterile surgical gloves available; these should be specifically designated as ready for polar bear cub rearing. (B338.24.w24)
    • Research milk formulations; discuss with other institutions which have reared cubs. (B338.24.w24)
    • Keep some polar bear serum frozen (as a source of immunoglobulins if the cub has not suckled colostrum from its dam). (B338.24.w24)
    • Prepare a written plan for rearing the cub; this should be discussed and reviewed ahead of the expected cub birth. (B338.24.w24)
  • Normal body temperature for a polar bear cub is: initially, 36.0 C (96.8 F), rising to 36.2 - 37.2 C (97-99 F) and by one to two weeks, 37.8 C (100 F). (B338.24.w24)
    • In adults, normal body temperature is 36.8-38.8 C; 
  • Polar bear milk is very high in fats and low in carbohydrates. Information on polar bear milk composition is available in: Polar bear Ursus maritimus - Life Stages (Literature Reports) - Lactation. Milk replacers available usually have a lower percentage fat and a higher percentage carbohydrates. Adipose tissue of cubs which had been mother-reared in the wild was noted to contain 31.7% saturated fatty acids, 48.5% monounsaturated and 15.5% polyunsaturated fatty acids. (J54.25.w2)
    • Liquid Esbilac on an as-fed basis contains 85% water, 5.4% fat, 4.6% protein, 4.1% carbohydrate and 0.9% ash. Of the fats, 24.2% are saturated fatty acids, 26.1% monounsaturated and 48.7% polyunsaturated - much higher polyunsaturated and lower saturated and monounsaturated fats than in polar bear milk. (J54.25.w2)
    • Cream contains 57.7% water, 2.1% protein, 2.8% carbohydrate, 0.5% ash and 37% fats, with 62.0% of the fats as saturated fatty acids, 28.0% monounsaturated and 3.7% polyunsaturated. (J54.25.w2)
    • Half-and-Half contains 80.6% water, 3.0% protein, 0.7% ash, 4.3% carbohydrate and 11% fat including 62% saturated fatty acids, 28.0% monounsaturated fatty acids and 3.7% polyunsaturated fatty acids. (J54.25.w2)
    • Cod liver oil contains 22.6% saturated fatty acids, 46.7% monounsaturated fatty acids and 22.5% polyunsaturated. (J54.25.w2)
    • Herring oil contains 19.8% saturated fatty acids, 58.6% monounsaturated fatty acids and 18.8% polyunsaturated. (J54.25.w2)
    • Fish oils, rather than vegetable oils, cream or half-and-half, may provide a much more suitable fatty acid distribution for adding to milk formulas for polar bear cubs. (J54.25.w2)
    • For further information on polar bear milk see: Polar bear Ursus maritimus - Life Stages (Literature Reports) - Lactation
  • Polar bear cubs should be introduced to water gradually and may take a couple of weeks to learn to swim and dive properly, but are then likely to enjoy spending hours in the water. (N30.74.w1)
Complications/ Limitations / Risk
Equipment / Chemicals required and Suppliers
  • Milk replacer: Esbilac Powder or Milk Matrix 33/40.

  • Feeding bottles and nipples.

  • Isolette, incubator or heated box, with appropriate lining and padding.

  • Equipment for sterile care - gloves, sterilising fluid for bottles etc.

Expertise level / Ease of Use
  • Rearing bear cubs is time-intensive and requires dedication and experience.
  • The caregiver(s) must fulfil the role of surrogate mother for the cub(s) for an extended period to meet the emotional needs of the cub(s). (B338.24.w24)
Cost/ Availability
  • Hand-rearing of young bear cubs requires a considerable time investment.
Legal and Ethical Considerations
  • Zoo-born bear cubs should not be hand-reared as a matter of routine. Failure of females to rear cubs usually occurs due to disturbance; every effort should be made to avoid the female being disturbed.
  • Orphaned/abandoned wild-born bear cubs should not be taken for hand-rearing if they are of an age where they are likely to survive alone.
  • Hand-rearing should not be started unless the carer is prepared to give the time and effort required for rearing to release, or to ensure that appropriate care will be continued through to release. 
  • Consider whether hand-rearing is the best option for the individual compared with leaving it in the wild. 
  • Consider whether euthanasia is a more humane/kinder option for the individual than attempting hand-rearing. 
  • If wild-born cubs are hand-reared, every effort should be made to rear them with conspecifics, and to ensure that the cubs are maintained suitable for release, preferably not habituated to humans, dogs etc. 
  • The US Fish and Wildlife Service does not recommend the release of hand-reared 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)
    • Released cubs would probably starve or be predated by an adult polar bear. (D259.VIII.w8)
Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee Gail Hedberg (V.w106)
References B123.19.w19, B338.24.w24, B379.37.w37, D251.8.w8, D259.VIII.w8, D315, J23.11.w3, J23.11.w4, J23.12.w2, J23.14.w3, J23.39.w1, J54.25.w2, N30.74.w1, V.w106

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