TECHNIQUE

Hand-rearing Lutra lutra - European Otter (Wildlife Casualty Management)
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Summary Information
Type of technique Health & Management / UK Wildlife Casualty Management / Techniques:
Synonyms and Keywords N.B. This information should be read in association with Hand-rearing of Orphaned Wildlife which contains background information together with links to the Electronic Library and Organisations (UK Contacts). The related Species pages contain similar linkages.
Description This page has been prepared for the "UK Wildlife: First Aid and Care" Wildpro module, and is designed for the needs of the following species: Lutra lutra - European otter
  • Ensure cubs have permanently lost contact with their family before taking for hand-rearing.
  • Female otters normally leave young cubs temporarily unattended, but a cub found wet, cold and stressed after being washed away by a flash flood would require rapid attention. (P19.3.w3, J35.147.w1)

Initial Care: 

General mammal information: 

  • On arrival any young mammal should be weighed, warmed, stimulated to urinate/defecate and given supplementary fluids by an appropriate route to counteract dehydration. 
  • The age should be determined if possible. (See individual species information page, sections "Appearance - Neonate" and "Life Stages - Reproductive stages").
  • The first feed given should be an oral rehydration (electrolyte) solution (e.g. Lectade, Pfizer Limited), with a gradual changeover to a milk substitute over several feeds.
  • See: Hand Rearing of Orphaned Wildlife for further general information. for further general information.

Otter specific information:

  • Check the cub's temperature; this should be 37.2-38.2C.(D51)
  • Cubs are likely to be dehydrated, underfed and stressed on presentation; in some cases dehydration will be severe and the cub hypothermic and starved. (D57)
  • Traumatic injuries and other medical problems may be found on presentation.(D57)
  • Give oral rehydration (electrolyte) solution such as Dioralyte or Lectade (Pfizer Limited) with a bottle or if necessary by stomach tube if the cub is not seen to drink fluids offered in a bowl.(D51)
  • Provide bedding such as towels or straw.
  • Provide heat using a heat lamp or heat pad.
  • Ensure the accommodation provides sufficient room for the cub to move away from the heat source if it becomes too hot.(D51)
  • A prophylactic course of antibiotics should be given as signs of illness may not be apparent until the cub is seriously ill.(D51)

General Care (including warmth and hygiene):

General mammal information

  • Young mammals have poor ability to maintain body temperature and are prone to hypothermia, hyperthermia and burns, particularly when unfurred.
  • Keep out of draughts but ensure ventilation is adequate.
  • Provide a temperature range, e.g. by heating one end of the container more than the other, which, while not allowing either overheating or chilling, permits the animal to chose the position at which it feels most comfortable.
  • The container used should be sufficiently large to allow the occupant to move into a comfortable position.
  • The sides of the container should be sufficiently high to prevent the occupant falling out.
  • Bedding materials should be soft, comfortable and either disposable or easily washed. They should keep the animal dry and be changed as frequently as necessary to prevent soiling.
  • (B194, P3.1987.w5, V.w5)
  • Maintain small mammals initially at 32C, then 28C, later 23C.(P3.1987.w5) Initially at 95F for a hairless baby, 90F for a haired infant with the eyes still closed, and reduce by 5F per week once the eyes are open.(B194)

Otter specific information:

  • Rear in compatible groups of two or three otters if possible.(P19.3.w3)
  • Raise in seclusion, with minimal human contact.
  • Leave a small bowl of rehydration (electrolyte) solution in with the cub so that it can drink between feeds.(D51)
  • Keep feeding utensils sterilised.(D58)

Milk replacer:

  • Eurasian otter milk contains:
    • Solids 38%, of which fat 63%, protein 28.9% and carbohydrate 0.3%.
  • Suggested milk replacers include: 
    • Zoological Milk Substitutes 30/55.(D51)
    • One part Esbilac (Pet Ag), two parts water, one part Multimilk, one part whipping cream, plus Fish Eater Tablet (Special Diet Services) and cod liver oil. (D51)
    • Mixture of Esbilac and liquidised white fish.(D51)
    • Mixture of white fish (skinned, boned and liquidised), boiled water, milk replacer for carnivores (puppies, kittens or zoo carnivores), cod liver oil and fish-eater vitamin supplement (Fish Eater Tablet, Special Diet Services).(D58)
    • If diarrhoea occurs give oral rehydration fluids as a substitute for at least one feed and increase total fluid intake. (D58)

Utensils:

  • Suitable-size pet feeding bottle.
  • Suitable sized syringe.(D58)

Feeding Frequency:

General mammal information: 

  • Varies depending on species.
  • In general, every 2-3 hours during the day and longer intervals at night.(P3.1987.w5)

Otter specific information:

  • Eight feeds a day for very young animals, gradually reducing to four or five feeds a day by weaning age.(D58)

Feeding Technique: 

General mammal information:

  • To encourage feeding in very small animals, place a drop of milk on lips, preferably with animal held upright.(P3.1987.w5)
  • Encouraging feeding in larger animals - insert teat in mouth, directed towards roof of mouth, and massage throat gently to encourage swallowing.(P3.1987.w5)

Quantities:

General mammal information:

  • Energy intake (kilocalories per day) = 200-250 x bodyweight (kg) 0.83. (P19.1.w5, P3.1987.w3)

General carnivore information:

  • May be fed up to 35-40% of body weight per day, and about 25-50ml/kg per feed. (J34.9.w1)

Otter specific information:

  • Feed 10-20% of body weight per day.(D51)

Toileting: 

General mammal information:

  • Most infant mammals require gentle stimulation of the ano-genital area (using e.g. a damp cotton bud, damp cotton wool or damp soft paper towel) in order to urinate and defecate. 
  • This should be done when the animal is first presented and at every feed until voluntary elimination is observed.

Otter specific information:

  • Cubs should be toileted after each feed.(D58)

Weighing: 

General mammal information:

  • Weigh daily.
  • If more than one infant is being reared in a litter, the infants may be marked in a safe manner e.g. using a small amount of a non-toxic coloured correction fluid such as Tippex in order to allow individual identification and monitoring. (V.w26)

Otter specific information:

  • A cub of 7-10 weeks old will weigh about 2-3 lbs.(D59)
  • Expected weight gain of approximately 0.65kg per month for male cubs, 0.45kg per month for female cubs, from two to ten months old.(D51)

Weaning:

  • Feeding:
    • Start weaning at 10 weeks old.(D51)
    • Feed slivers of good quality firm white fish, initially five times daily reducing over about one month to 2-3 feeds a day.(D51)
    • Supplement fish, particularly frozen fish, with vitamin tablets designed for fish-eaters (Special Diet Services) which contain thiamine (one Fish Eater tablet per 2kg body weight per day).(D51)
  • Accommodation:
    • At five to six months old move into an outdoor pen with a "holt" box for sleeping. See: Accommodation of Casualty Lutra lutra - European otter.
    • At about 8-10 months old move to a pen about 25m square containing natural vegetation and a pond with flowing water.(D51)
    • Keep in secure large outside large pens with access to water pools and other "features of interest". (P19.3.w3)

Release:

Appropriate Use (?)
  • Wild animals should not be taken for hand rearing unless they are definitely orphaned, abandoned or injured, or in immediate danger.
  • Hand-rearing is required for cubs which have been separated from their mother e.g. during a storm, or abandoned due to food shortage, or the mother is dead.(P19.3.w3, D59, J35.147.w1)
  • Cubs normally may be left unattended for a period of time.(J35.147.w1)
  • Cubs which become imprinted on humans have a reduced chance of survival after release.(D51)
Notes
  • Most likely to present in autumn/winter at 2-4 months old. (P19.3.w3, D24)
  • Preferably keep more than one cub together: for comfort, encouragement of social and physical development, reduction in risk of human bonding. (D59)
  • May be kept for a little longer than the time they would spend with their mother, therefore about a year, to release in spring to autumn (most favourable conditions). (P19.3.w3)
  • Local Wildlife Trust, English Nature (EN), Scottish Natural Heritage (SNH) or Countryside Council for Wales (CCW) should be able to arrange for a cub or cubs to be transferred to the nearest otter centre.(D59)
  • An ordinary outdoor thermometer may be used to indicate the temperature in the container used to house the orphan.(B194)
  • Routine records should be maintained of daily weight, times of each feed, quantities of milk consumed, urine/faeces production and general condition/demeanour. Such records provide an objective means of assessing progress and provide useful data for improving rearing methods.(V.w5)
  • Concentrated orange oil (from culinary suppliers, i.e. suitable for ingestion) is effective to make body parts used for "comfort sucking" unattractive.(D58)
  • Early weaning onto fish is recommended as providing a suitable palatable and nutritious milk replacer is difficult.(D58)
  • A stable routine and a single carer are important to encourage feeding.(D58)
Complications/ Limitations / Risk
  • Cubs normally may be left unattended for a period of time and may be identified wrongly as "orphans" at such times.(J35.147.w1)
  • Cow's milk must not be used as otters are lactose intolerant (cannot digest lactose). (D51)
  • Orphaned otter cubs require care for about 10-12 months with experienced handling, other otters for companionship and minimal handling to avoid taming.(D59)
  • Otter cubs even when only about five months old are capable of delivering a nasty bite.(D59)
  • Otter cubs may cause local irritation and infections by "comfort sucking" on body parts such as the penis, vulva, ears, tail or nipples of companions; some cubs suck similar parts of their own body.(D57, D58)
Equipment / Chemicals required and Suppliers
  • Esbilac (Pet Ag, Kruus UK Ltd., Unit 17, Moor Lane Industrial Estate, Sherburn in Elmet, North Yorkshire, LS25 6ES; Pet-AG Inc., Elgin, Illinois, USA): from pet stores.
  • Multimilk.
  • Zoological Milk Substitutes 30/55.
  • Fish Eater Tablets (Special Diet Services, PO Box 705, Witham, Essex, England CM8 3AD).
  • Concentrated orange oil is available from culinary suppliers.(D58)
  • Suitable outdoor pen in later stages prior to release.
  • Lectade (Pfizer Limited): from veterinary suppliers.
Expertise level / Ease of Use
  • It is strongly recommended that juveniles of this species are transferred to expert individuals or organisations as rearing and successful release requires considerable expertise and specialised pre-release accommodation.
  • While rearing by inexperienced persons may result in a physically healthy juvenile, the chance of survival after release may be seriously reduced if expert techniques have not been correctly applied.
  • Considerable time commitment involved.
  • Manual dexterity is important for caring for these small individuals. 
  • Requires empathy, observation skills and the ability to "read" the animal's body language.
  • Experience with hand rearing is useful and likely to greatly increase the success rate.
Cost/ Availability
  • Considerable investment in time is required for proper rearing and release.
  • The overall investment in supplies may be significant.
  • The cost of constructing suitable pre-release accommodation may be considerable.
Legal and Ethical Considerations
  • 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.
  • An offence may be committed under the Abandonment of Animals Act, 1960 Section 1 if a released animal does not have a reasonable chance of survival (i.e. a chance similar to its non-rehabilitated peers). It is an offence under this Act for a person having control or charge of an animal to abandon it permanently or otherwise in circumstances likely to cause unnecessary suffering. This may include release at an unsuitable site, in the wrong territory, unfit, not having learned to hunt, at the wrong time of year etc. (J35.147.w1, B156.21.w21, B223, W5.Jan01)
  • Otters are listed under Schedule 5 of the Wildlife and Countryside Act 1981.
  • See: Legislation relating to Wildlife Casualties for further information on legislation.
Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman
References

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