The Care of the Foal

PREPARATION FOR FOALING

Gestation period is variable and donkeys may be in foal without the owner’s knowledge. Care of the dam in preparation for foaling is essential.

• Regular assessment of the body condition of the female, avoiding changes in weight. Feed may be adjusted as appropriate.

• Vaccinations should be up to date. Booster vaccinations should be given within 1 month of parturition.
• Worming should be planned dependent on the results of a faecal worm egg count (FWEC)'. Worm one month before expected foaling using a wormer suitable for use with pregnant donkeys. Ensure pasture is managed to reduce parasite transmission.
• Routine healthcare should continue, including farriery and dentistry, but consider the risk associated with procedures that could cause excessive stress.

Signs of imminent foaling are similar to the horse and prediction of foaling is often based on udder development. The udder starts to enlarge and produce milk 3 weeks prior to foaling and 'waxing up' (colostrum oozing from the teats,) happens 24-48 hours prior to parturition. Colostrum colour may change from yellow to white just prior to foaling.

Electrolyte levels in the mammary secretions can be used to predict foaling. A sodium:potassium ratio of less than 1 is indicative of foaling occurring in the next 24–48. Calcium levels are less reliable but can also be used.

A complete equine foaling kit should be available, with the following items specifically for donkey foals:

• a male urinary catheter is useful for nasogastric intubation due to the smaller relative size of donkey foals (Portex horse catheter 137cm 6.7mm OD)
• a smaller IV catheter ( 20-22G) and needles
• a large dog-size thermal rug or blanket.

ROUTINE CARE OF THE NEWBORN FOAL

Normal donkey foals stand within 2 hours of birth and nurse from the mare soon after. They should be bright and alert with slightly different physiological parameters to a newborn horse foal.

Foals should consume 1-2 litres of colostrum within the first 12 hours of life. The first feed should be within 2-4 hours of birth. The recommended amount is 250mls every hour for the first 6 hours, making a total of 1.5 litres. Absorption rapidly falls to less than 25% efficiency by 3 hours of age, therefore foals should be encouraged to nurse as soon as possible.

If maiden female donkeys give birth in a large area it may be worth confining her in a smaller space e.g. a stable with the newborn foal until they have bonded to increase the chances of the foal being able to find the udder and suckle as soon as possible.

It is important for owners to check that the dam has accepted the foal and is producing sufficient colostrum. In maiden females, this latter can be an issue and in these cases, an appropriate colostrum substitute should be given.

Commercial horse colostrum can be used for donkeys.

Immunoglobulins type G (IgG) levels in the donkey neonate are directly comparable to horse foals and it is advisable to check routinely for passive transfer of antibodies, ideally 16- 24 hours after birth. The same commercial IgG foal-side tests such as SNAP tests are suitable for donkey foals.

Foals should be observed to pass meconium within 24 hours of birth and owners should be made aware to look for this.

Donkey foals tend to be lighter than the average horse or pony foal, although weight varies between individuals and breeds, ranging from 5—40kg. It is essential to estimate weight accurately when planning medication.

Despite their thick coat, donkey foals are not very cold tolerant, becoming chilled rapidly if they remain wet. Access to clean, dry shelter with appropriate bedding is important. If the weather is very cold, a safe heat lamp can be provided in the stable to help regulate environmental temperature. Due to the variable gestation length it can be difficult to plan breeding to avoid extreme conditions at the expected time of foaling.

The owner should be advised to dip the foal's umbilicus with an antiseptic solution appropriate for equine use.
 

Donkeys have specific physiological differences to horses and ponies, and these differences affect drug distribution and metabolism. These also apply to the donkey neonate. In the absence of specific pharmaceutical information, drugs and dosages considered appropriate for horse and pony foals and lactating mares can be applied to donkeys.

In the absence of specific pharmaceutical information, drugs and dosages considered appropriate for horse and pony foals, and lactating mares can be applied to donkeys.

COMMON CONDITIONS OF THE NEWBORN FOAL

The common conditions seen in newborn donkey foals are similar to those seen in horse and pony foals, but the donkey-specific differences need to be considered.

Prematurity

The donkey has a variable gestation period with a reported average length of 365—376 days with a range of 11 - 14.5 months. Therefore it can be difficult to classify a donkey foal as either:

• premature — i.e. born early according to stage of gestation
• dysmature — i.e. a foal whose maturity is not appropriate for its gestational age.

Clinical signs of prematurity are similar to those found in horses and ponies.
 

Meconium retention

The clinical signs and treatment of meconium retention in donkeys are similar to those in horses and ponies. Additional therapy including fluids, analgesics and laxatives by nasogastric tube can also be used in the donkey. Care must be taken when using a nasogastric tube due to the smaller size of donkeys foals. A male urinary catheter can be used as a nasogastric tube for newborn foals.

Failure of passive immune transfer (FPIT)

FPIT can be found in donkey foals as a result of poor colostrum quality and/ or quantity, or an inability of the newborn donkey foal to suckle. Pregnant donkeys in the last trimester and lactating donkeys have a high risk of developing hyperlipemia. This will have an adverse effect on colostrum quality and milk production respectively. Hyperlipaemia will increase the risk of FPIT.

The main reasons for the FPIT in the foal include:

• suckling or feeding with a low quality colostrum,
• a delay in the foal suckling
• a lack of absorption of IgG.

Early treatment of FPIT is usually effective if the suckle reflex is present and good quality colostrum is available.

If good quality colostrum is available the female can be milked by hand and the colostrum given to the foal by nasogastric intubation. Colostrum can be fed in this way entirely if the dam rejects the foal, or partially if supplementary feeding is necessary.

If colostrum cannot be collected from the dam, frozen colostrum can be used. If neither is available, commercial horse colostrum can be used. Take care when defrosting frozen colostrum, it must be fully defrosted without denaturing the antibody proteins and should be warmed before administration.

Risk factors are similar to those in the horse and pony, with an incidence of up to 40% reported. IgG concentrations considered normal in horse and pony foals are also applicable to the donkey foal.

• Average sized foals should consume 1—2 litres of colostrum, depending on their size, within the first 12 hours of life.
• The first feed should be within 2—4 hours of birth.
• The recommended amount is approximately 250mls every hour for the first six hours, making a total of 1.5 litres.
• Absorption rapidly falls to less than 25% efficiency by three hours of age. Foals should be encouraged to nurse as soon as possible, whilst considering the need to maintain the bond between the dam and foal.

Colostrum quality can be assessed with a refractometer and a specific gravity greater than 1.080 and/or a Brix score greater than or equal to 20% is considered accepable.

To carry out nasogastric intubation in a donkey foal:

• a male urinary catheter 20F (Portex) might be preferable to a horse foal nasogastric tube
• ensure the end is capped to avoid aerophagia
• nasogastric tubing in donkey foals is also a risk factor for gastric ulceration and the use of omeprazole may be indicated.

Plasma transfusion is recommended if no adequate passive transfer is verified after 24 hours post-partum, and after 12 hours in selected cases. Although expensive, hyperimmune plasma transfusion should be considered in the treatment of FPIT in donkey foals as an alternative to collecting plasma from the dam. Commercial plasma can be widely obtained in the UK. Estimate the weight of the foal accurately to ensure appropriate volumes are given.

In the experience of The Donkey Sanctuary, IgG levels directly compare to those found in horses and the same approach should be taken when IgG is less than 800 mg/dl. Supplementation with plasma has proven very successful after only one administration, although more than one administration has been reported to be necessary. IgG levels can be checked 8—12 hours after birth, although 16—20 hours after birth is common practice.
 

Catheter placement and administration of plasma are facilitated by sedating the foal. Good levels of sedation in the donkey foal have been achieved with diazepam I/V at 0.1—0.25mg/kg. Keeping the dam occupied with a small feed may be helpful, as she might be very protective of the foal.

Neonatal septicaemia and diarrhoea

Presentation, clinical signs and treatment are the same as in the horse and pony, with problems of dysmaturity, hypothermia and FPIT potentially occuring concurrently in the same individual. Nutritional support, fluid therapy and gastric ulcer preventative treatment follow standard equine practice.
 

Gastric ulcers

The prevalence of gastric ulcers in foals has been reported to be between 25—57%. Risk factors and clinical signs are comparable to those in horses.

Prevention and treatment with omeprazole and/or sucralfate at the standard equine dosage are appropriate. Omeprazole is not licensed for foals less than four weeks old or weighing less than 70kg. However, its effective use has been extensively reported.

Congenital anomalies

Abnormalities of the head and jaw have been observed in donkey foals. These may cause dystocia and/or affect suckling. Other congenital abnormalities have been reported in donkeys, including patella luxation, atresia and flexural limb deformity.

White muscle disease

Adult donkeys can be affected but foals are more susceptible to nutritional muscular dystrophy from selenium and vitamin E deficiency. Clinical signs are the same as those found in horses and ponies. Treatment and prevention can be achieved using standard equine doses of selenium in donkey foals and/or by supplementation with selenium in female donkeys.

THE REJECTED AND ORPHAN FOAL

A female donkey may show antagonistic behaviour towards her foal after birth. Common predisposing factors are:

• pain – for example mastitis
• behavioural problems related to fear, which may be attributed to the presence of humans and/or inappropriate behaviours or interference by them
• previous rejection of a foal.

Providing owners are aware of this, prevention is sometimes possible.

Rejected foals are in danger of being severely injured.

Time is essential because the foal must receive colostrum early followed by a regular milk supply. A foal that doesn’t suckle in the early stages of life will lose the instinct to do so. To reduce chances of rejection keep the mare and foal together directly after birth in a confined area so that the foal can find the dam.

Overcoming rejection of a foal is not easy and may be impossible. The chances of success are poor if the foal is not accepted within the initial 10—12 hours after birth.

• The dam and foal should be in a calm environment and separated by a partition that allows them to see and smell each other.
• The dam and foal should be put together when the foal is hungry and the dam has a full udder.
• Allow the dam and foal to meet at frequent intervals, but take care to avoid negative behaviours during the meetings.
• Positive reinforcement of the dam using treats may result in a calming effect, but in some cases may cause more anxiety.
• A strong smell (for example Vicks VapoRub) placed over the dam’s nostrils and on the foal, especially on head, neck and hindquarters may help.
• Chemical tranquilisation may be used, but the need should diminish at each subsequent meeting.

Foster mothers are the best solution for orphan foals but are rarely available. Foster mothers may include donkeys:

• whose foal died or has been weaned
• who are already feeding a foal
• in whom lactation is induced.

A donkey that has just lost her foal is the best candidate for orphan foal fostering, but fostering can also be successful using donkeys whose foal has been weaned.

Success is increased where:

• the donkey has suckled her dead foal, and the period between foal death and orphan foal introduction is short; after 2—3 days the donkey’s milk may dry up
• the donkey is moved to an alternative stable that she does not associate with her dead foal
• the amnion, meconium or hide from the dead foal is smeared over the orphan before the orphan is presented to the female donkey; in herd situations amnions and/or meconium can be usefully frozen in advance for this purpose.

A female donkey may not accept a second foal when she is already feeding. If she does it is important to consider nutritional supplementation of both the female donkey and the foal(s). Foals can be given access to a milk replacer – for example in a bucket. Horse milk replacer is an appropriate milk substitute, as are foal creep pellets (milk-based pellets) if the foal is no longer newborn.

Patience and continued attempts may be needed if adoption is to occur. It is possible to make an extremely hostile donkey a good mother.

Protocol for hand-rearing

The successful hand-rearing of donkey foals follows the same principles as for horses and ponies. Ensure a donkey companion is present at all times to avoid behavioural problems later in life.

Fresh donkey milk is preferable but, if unavailable, horse or goat milk or horse milk replacer should be used.

With regard to the frequency and volume of milk, consideration should be given to the following:

• Milk should be warmed to 38°C for initial feeds, gradually reducing to air temperature over the first week.
• Diet changes should always be made slowly over 24 to 48 hours.
• A 10kg foal requires 30kcal/kg (125kJ/kg) per day, while a sick or premature foal requires 36kcal/kg (150kJ/kg) per day.
• The recommended volume of milk for a healthy foal is 100ml/kg bwt per day (10% of its bodyweight).
• A foal sucks from the mother about seven times a day. Ideally it should be fed at 2 to 3 hourly intervals, although during the first week it is preferable to feed every 1 to 2 hours. If the foal is sick, it may be unable to tolerate more than 50 to 100mls every hour, so more intensive rearing is required. As it improves this volume can gradually increase to 200mls an hour.
• Foals usually do not overeat but caution is recommended. Milk should be given in small quantities and often, because an excessive quantity of milk in one meal may swamp the digestive enzyme system and acidity of the stomach, leading to the proliferation of pathogenic enteric microorganisms.
• Only use recently prepared fresh or powdered milk to avoid bacterial development. Hands and utensils should be kept clean.
   

A suggested hand-rearing protocol:
 

Be aware that nutritional diarrhoea and lactose intolerance may occur in donkeys. Management and treatment is the same as for horses and ponies.

Artificial Suckling

An alternative method of feeding an orphaned foal is to use an artificial suckling system. This uses a milk-warming machine that will heat milk as required when the foal sucks on the teat. The teat can be attached through a hole in the stable door, with the apparatus set up outside, allowing the foal to obtain ad-lib milk 24 hours per day. The benefits include:

• an ability to perform a more natural pattern of suckling behaviour
• a reduction in stress caused by the inability to suckle at the times the foal chooses
• allowing the foal to consume smaller quantities of milk more regularly instead of consuming a large quantity at regimented intervals.

A potential drawback is that the foal may pass loose stools while on the system, and so the foal will need to be monitored carefully. Gradually reducing quantities during weaning will help to reduce this problem.

WEANING

At The Donkey Sanctuary we recommend weaning around a year old.

Different weaning options have been reported for horses and ponies, and these can be employed for donkeys. However, gradual weaning is considered to be the best approach from a behavioural point of view. It is important to monitor weaning closely to avoid excessive stress and to prevent the risk of hyperlipaemia. Although the feeding requirements of the female donkey will be reduced, offering small but more frequent feeds for a period of time might be of benefit.