Management of premature and twin foals
Figure 1. Floppy ears are a sign of a sick foal.
A normal equine pregnancy lasts 340 to 360 days. Foals born prior to 340 days usually have distinct physical characteristics and are considered premature. Twins and infection and thickening of the placenta and are the most common causes for premature delivery. Premature physical characteristics can also occur in some foals born after 340 days. In this case, the foals are considered dysmature. Dysmature foals may be the result of placental insufficiency, nutritional factors, or often unknown causes. Premature and dysmature foals have very special needs.
Signs of prematurity in foals include low birth weight, domed forehead, floppy ears, silky hair coat, lax tendons and poor muscle development (Figure 1). Often premature /dysmature foals do not have the strength to stand by themselves. This makes it difficult for them to nurse adequately. When standing, the front knees may seem to sink backwards and the fetlocks may touch the ground.
Premature foals are at very high risk for life threatening complications. Lack of mature lungs means difficulty in getting adequate oxygen and a predisposition to suddenly developing respiratory distress. Because the suckle reflex in premature foals is often weak, they may not get adequate colostrum or nutrients, foals may aspirate milk into the lungs resulting in pneumonia. In addition, important antibodies from colostrum may not be absorbed by an immature gut which further predisposes foals to infection.
Foals need to nurse at least once an hour. Weakness and laxity in the tendons of the limbs may prevent foals from standing for long enough to nurse adequately. If premature/dysmature foals can stand, they may crush immature bones in their front knees and hocks. Crushing these poorly calcification small bones leads to limb deformities, chronic arthritis, and limited future athletic performance.
Even though premature/dysmature foals look bright and nurse well immediately after birth, their status can change in an instant.
It is critical to recognize the signs of prematurity/dysmaturity at birth. The continuous veterinary care these foals need is beyond the scope of most horse owners. Preventing complications from arising, providing adequate nutrition, and ensuring restricted exercise from the first few hours after birth are key to success. Foals need to be watched for signs of respiratory distress, infection, dehydration, malnutrition, and intestinal dysfunction. Oxygen therapy, broad spectrum antibiotics, intravenous fluids, assistance to nurse hourly, or placement of a feeding tube are common therapies provided for premature/dysmature foals.
Radiographs are commonly taken to detect the extent of improper ossification. Support for the legs and restricted time standing can be implemented to try and prevent permanent damage to bones. Owning a premature foal can be an emotional roller coaster as the foal's status can fluctuate for several weeks until the foal stabilizes.