TECHNIQUE

Hand-rearing Squirrels (Wildlife Casualty Management)

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: Sciurus carolinensis - Eastern grey squirrel, Sciurus vulgaris - Eurasian red squirrel.

These species are within the family Sciuridae.

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 pages, 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.

Squirrel specific information:

The following guide to ageing of Sciurus vulgaris - Eurasian red squirrel is taken from "Management Guidelines for the Welfare of Zoo Animals: Red Squirrels". (W163)

  • New born - they are blind and deaf, their skin is pink and devoid of hair except for short whiskers. They weigh approximately 11-15 grams, or 8-12 grams.
  • 1 to 5 days - Young uncoordinated, movements consist largely of treading and clutching.
  • 1 week - Still pink with very small whiskers which are about 1mm in length.
  • 5 to 10 days - Capable of emitting alarm calls.
  • 2 weeks - a light fuzz of hair along the back though belly and limbs are still bare.
  • 15 to 20 days - Quiet `cooing` sounds are made prior to feeding.
  • 25 days - Still totally blind, weigh approximately 56 grams, hair on tail 3mm, on back 2mm, on ear tip 2mm. From tip of nose to base of tail measure about 105mm, the tail exclusive of hairs is 70mm, hind leg with nails 65mm, front leg 46mm. Longest whisker 15mm.
  • 3 to 5 weeks - eyes and ears open, muzzle head and tail quite well furred. Approximate weight is 50 grams.
  • 19 to 23 days - Lower incisors show, co-ordination and power of movement improve.
  • 4 weeks - Able to climb out of the nest, claws well developed.
  • 35 days - The legs are able to support the body.
  • 5 to 6 weeks - Whole body is covered in hair. Lower incisors are prominent and lower incisors start to show.
  • 7 to 9 weeks - Begins to leave nest. Weight approximately 110-130 grams. Weaning begins.
  • 8 weeks - Weight around 85 grams, longest whisker 37mm, tail exclusive of hair is 135mm.
  • 10 to 11 weeks - Weaned.
  • 13 weeks - Independent.
  • Adult - Weight between 220 and 430 grams.

General Care (including warmth and hygiene):

  • General mammal information
    • 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)
    • 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)

Squirrel specific information:

  • Cardboard box, lined with hay or with e.g. old socks or shredded tissues provides suitable accommodation. (B156.12.w12, D25)
  • Box should be kept closed, or covered with e.g. a wire screen, to avoid escapes, as squirrels are good climbers.(B196, D25)
  • A constant not fluctuating temperature should be provided, including when the squirrel is being fed. (B196, V.w22)
  • Hot water bottle under hay or other bedding is suitable as a heat source. (B156.12.w12, D25)
  • Keeping the infant's container in an airing cupboard has been used successfully to provide uniform warm ambient temperature.(W163)
  • Suggested by Stichting Eekhoornopvang in the Netherlands to keep at 30-33C room temperature.(W163)
  • Maintenance of a high standard of hygiene is vital; a variety of disinfectants have been used.(W163)
  • Small cage with an internal nest box filled with nesting material made up of woodwool, hay and paper tissues; no extra heat provided (used for infants from about one month old at Zoological Society of Wales).(W163)

Milk replacer:

  • Squirrel milk is high in dry matter and high in fat.(B156.12.w12)
  • Composition 39.6% solids, 67% fat, 20% protein, 10% carbohydrates and 2.85 Kcal/ml.(W163)
  • Suggested milk replacers include:
    • Goat's milk, with added calcium-phosphorus supplement (Stress, Philips Yeast Products) once daily.(B151)
    • Esbilac (Pet Ag) or Lamlac (Volac) may be suitable. (B156.12.w12)
    • Puppy milk replacer, lamb milk replacer or goat's milk.(D25)
    • Avoid changing the type of milk used.(D25)
    • Goat's milk.(B195)
    • Ratio of 50:50 mix of milk and water with a pinch of glucose added. (B224)
    • Mix made from water, sunflower oil, lactose free baby powder, calcium and multi vitamins, offered at body heat (used by Stichting Eekhoornopvang in the Netherlands).(W163)
    • Goats milk without additives, fed warmed. (W163)
    • Cow's milk diluted by boiled water and with a little glucose added.(W163)
    • Cimicat (Petlife) kitten milk replacer, with or without a little added glucose.(W163)
    • Lactol (Shirley's), made up one part milk powder to three parts water, with or without a little added glucose.(W163)
    • Addition of a little brown sugar has been suggested to treat constipation. (W163)
  • Suggested additives include:
    • Abidec multivitamins (Parke-Davis), a drop added to the first feed each day or twice weekly.(W163)

Utensils:

  • Pipette or small syringe.(B197, B224)
  • Small syringe (0.3ml syringe to four weeks old thereafter 1ml syringe) is used by Stichting Eekhoornopvang in the Netherlands.(W163)
  • 1ml syringe tipped by a Mikki teat was used by the Zoological Society for Wales for squirrels starting at about one month old.(W163)
  • Catac kitten bottle or similar with a small soft rubber teat has been used.(B151, B195, W163).

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)
  • More frequent feeding (e.g. every hour) may be required for very small species, particularly for neonates.(V.w5)

Squirrel specific information:

Suggested rearing protocols include:

  • Four to five feeds per day.(B151)
  • Every two hours initially, decreasing to every four hours at about three weeks old (eyes open).(B197, D25)
  • 5-6 feeds per day with up to a six hour period without feeding overnight.(B224)
  • Schedule used by Stichting Eekhoornopvang in the Netherlands to rear at least 130 squirrels:
    • 0-2 weeks old 1/2 ml feed every 2 hours
    • 2-4 weeks old 1/2-1 ml feed every 2-3 hours
    • 4-6 weeks old 1-2 ml feed every 3-4 hours
    • 6-8 weeks old 2-3 ml feed every 4 hours
    • 8-10 weeks old 4-5 ml feed every 5 hours
    • (W163)
  • Every three hours (schedule used by Lakeland Oasis and by a private individual). (W163)
  • Every three hours with a break of six hours overnight (schedule used by Scottish SPCA and Highland Wildlife Park).(W163)
  • Three to five times daily for squirrels weighing about 90-110 grams.(W163)
  • Every 2-3 hours, 6am to 11pm (schedule used by Zoological Society of Wales). (W163)

Feeding Technique: 

General mammal information: Encouraging feeding:

  • To encourage feeding in very small animals, place a drop of milk on lips, preferably with animal held upright.(P3.1987.w5)
  • To feed using a medicine dropper:
    • Hold the infant in one hand with its head slightly higher than its body, place the dropper just inside the animal's lips and press the bulb extremely gently to place a tiny drop of formula in the infant's mouth to encourage feeding to start. As it begins to suck or lick the dropper may be pressed very gently to assist the infant to take the formula.(B194)
    • If a bubble of liquid appears at the nose or the infant opens its mouth wide, immediately stop feeding and tilt the infant head down to allow the excess formula to drain from its mouth. Give the infant a chance to recover then start again more slowly.(B194)
    • Refill the dropper as required.(B194)
    • Some infants may feed by licking individual hanging drops of the end of the dropper.(B194)
    • Clean any excess from the infant's nose/chin after each feed.(B194)
  • A similar technique can be used with a small syringe, pressing very slowly on the plunger as the infant sucks or licks.(V.w5)
  • When feeding very small neonates it is vital that the feeding technique used provides milk at a sufficiently slow rate to minimise the risk of milk being inhaled with resultant aspiration pneumonia.(V.w26)

Squirrel specific information:

  • Present in a syringe, using a 0.3ml syringe for infants up to four weeks old and a 1ml syringe thereafter (used by Stichting Eekhoornopvang in the Netherlands to rear at least 130 squirrels). (W163)
  • Squirrels may be greedy feeders and care care should be taken to ensure they don't choke.(B224)

Quantities:

General mammal information:

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

General rodent information:

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

Squirrel specific information:

  • Small amounts at each feed initially, with as much as the squirrel will take at each feed by three weeks.(B197, D25)
  • 5ml per day taken at 15 days old increasing to 15ml per day at 28 days old.(W163)
  • Up to 2.5ml taken in the first feed of the day followed by an average of 0.5-0.75ml per feed (for schedule of every 2-3 hours, 6am to 11pm) by infants of about one month old, increasing to as much as 5-7ml per feed close to weaning (Zoological Society of Wales).(W163)
  • 1.5-6ml per feed taken by a squirrel fed five times daily with Cimicat and with an initial body weight of 105g.(W163)
  • 3-11ml per feed taken by a squirrel fed three times daily on Esbilac (Pet Ag) and with an initial body weight of 90g.(W163)

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.
  • Squirrel specific information:
    • Squirrels should be stimulated to urinate and defecate at each feed until they are regularly urinating and defecating on their own.(B195)

Weighing: 

General mammal information:

  • Weigh daily. 

Weaning:

Suggested weaning protocols include:

  • It is important to introduce squirrels to as wide a range of foodstuffs as possible in the formative learning months after first leaving the nestbox. Individuals which are offered only a few different food types may ‘fix’ on these items and become unwilling to try new foods or perhaps even to recognise novel food items. (W163)
  • Liquidised fruit babyfood may be added to the milk to start the weaning process (suggested by by Stichting Eekhoornopvang in the Netherlands).(W163)
  • Two squirrels hand reared from under two months old and offered solid foods at all times started to nibble at food at about 45 days old, with apple and Shaws egg biscuit as preferred foods initially and milk feeding was refused constantly by 45 days. (W163)
  • Wean at 2-3 weeks; start weaning with Farley's rusks, gradual change to good-quality dry puppy food.(B151)
  • Wean onto soft food initially by soaking bread in milk and fruit. Once teeth have erupted offer foods such as bark and dog biscuits to chew on, then provide a variety of foods.(D25)
  • Bread soaked in milk may be used as an initial weaning food.(B224)
  • Dry breakfast cereals (oat or wheat based) and nuts initially, then fruits such as apple, orange sections, grapes, carrots etc. (B194)
  • Provide natural foods if possible to ease the transition to finding food on release. (B194)
  • Totally weaned by about 8 weeks.(D25)
  • Avoid feeding with peanuts and sunflower seeds.(B151)
  • First add baby cereal and/or baby food to the milk. For the first dry food, offer dry breakfast cereals (e.g. oat or wheat based) and nuts initially. Once the infant is eating well add fruits and other foods, e.g. grape, orange, apple, green lettuce, wholemeal bread, carrot and wild seeds. Ensure the infant eats a good range of foods.(B194)
  • See: Feeding of Casualty Squirrels

Release:

  • Under Schedule 9 of the Wildlife and Countryside Act 1981 it is illegal to release a Sciurus carolinensis - Eastern grey squirrel or to allow one to escape.
  • Soft release is required for hand-reared red squirrels.
  • It has been suggested that hand-reared red squirrels may not be good candidates for release and may more appropriately be incorporated in the captive breeding programme from which their offspring may then join the organised release programme. (W163)
Appropriate Use (?)
  • Wild animals should not be taken for hand-rearing unless they are definitely orphaned, abandoned or injured, or in immediate danger.
Notes
  • Squirrel milk is high in dry matter (i.e. high concentration) and high in fat. (B156.12.w12)
  • Considerable initial commitment of time and effort when frequent (two-hourly) feeding is required.
  • An ordinary outdoor thermometer may be used to indicate the temperature in the container used to house the orphan.(B194)
  • Efforts should be taken to avoid hand-reared infants becoming imprinted.(W163)
  • Colour dyes, bleaching or coat clipping may be used to distinguish individuals in the short term. Implanted Trovan microchips are recommended for long term identification of individuals.(W163)
  • Practice with fine control of a syringe is required to enable milk to be slowly.(V.w5)
Complications/ Limitations / Risk
  • Susceptible to hypocalcaemia (B151)
  • It has been suggested that the use of peanuts and sunflower seeds in weaning diets should be avoided.(B151)
    • Peanuts and sunflower seeds are highly palatable, high in fat and low in calcium. Individuals weaned onto these food items may prefer them to the exclusion of other foodstuffs resulting in an unbalanced diet, a high risk of nutritional diseases and a high risk of starvation if the individual is released as it may not eat natural foods.(V.w5)
  • Hairless, blind infants are relatively difficult to rear; older, well-furred individuals are more difficult.(B195)
  • Risk of constipation and urine retention if the infant is not stimulated to urinate and defecate at each feed.(B195)
  • Intersucking (sucking on one another) is an abnormal behaviour pattern which can be seen in litters of squirrels reared in the absence of a mother from which to suckle. Squirrels may show "penis sucking" behaviour which may cause sufficient trauma (sufficient) to require temporary or permanent removal of affected males.(B224)
  • The use of a small syringe rather that a pet feeding bottle may increase the degree of control over feeding and reduce the risks of milk being presented too fast and causing choking or milk inhalation. (W163)
  • Imprinted squirrels are poor release candidates and are also less likely to be good breeders; efforts should be taken to avoid imprinting.(W163)
  • Re-sterilised syringes should be discarded when the plunger begins to stick as the additional pressure required to move the plunger may result in excessive quantities of fluid being accidentally deposited in the infant's mouth. (V.w5)
Equipment / Chemicals required and Suppliers
  • Suitable milk replacer:
    • Lactol milk replacer for small mammal: (Sherley's Division, Ashe Consumer Products Ltd., Leatherhead, Surrey, UK.).
    • Goats' milk: Many supermarkets and health food stores.
    • Esbilac: (Pet Ag, Kruus UK Ltd., Unit 17, Moor Lane Industrial Estate, Sherburn in Elmet, North Yorkshire, LS25 6ES, UK).
    • Lamlac (Volac Ltd., Orwell, Royston, Hertfordshire, UK).
    • Cimicat (Petlife, Minster House, Western Way, Bury St Edmunds, Suffolk, 1P33 3SU)
  • Stress (Philips Yeast Products).
  • Farley's Rusks: (H.J. Heinz Co. Ltd., Hayes, Middlesex, UK).
  • Catac cat bottle and teat, small syringe or pipette.
Expertise level / Ease of Use
  • Considerable time commitment involved, particularly initially if two-hourly feeding is required.
  • Manual dexterity is important for caring for these very small individuals. OR (Manual dexterity important.)
  • 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
  • Products and equipment all widely available, not particularly expensive.
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)
  • See: Legislation relating to Wildlife Casualties.
  • Grey Squirrels (Prohibition of Importation and Keeping) Order 1973 of the Destructive Imported Animals Act 1932: prohibits the keeping of Sciurus carolinensis - Eastern grey squirrel, without a licence. Licences are issued by MAFF (now DEFRA).(J35.147.w1)
  • Grey squirrels are listed in Schedule 9 of the Wildlife and Countryside Act 1981; under Section 14 of that Act it is illegal to release a grey squirrel or to allow one to escape.
  • Sciurus vulgaris - Eurasian red squirrel should preferably be released as part of an organised reintroduction programme - into ideal habitat. Contact The Mammal Society or Peter Dickinson (V.w21).
  • Alternatively, a hand reared Sciurus vulgaris - Eurasian red squirrel may be useful as part of the ongoing captive breeding programme for this species in the UK. (V.w5)
  • See: Legislation relating to Wildlife Casualties.
Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman
References

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