Description

With a normal gestation period considered to be 345 days, a foal delivered before the 320th day is considered to be premature. Foals delivered early are vulnerable to infection that may be passed on from the mare or contracted through outside sources.

In addition, organs and bones may be under-developed, leading to respiratory and cardiac problems, along with soft, weak bones that cause problems for the foal when it attempts to stand.

If the mare is seriously compromised because of the premature delivery, she may not produce the colostrum the foal needs to fight bacterial infections.

If the foal cannot stand to nurse because of under-developed or crooked leg bones, care will need to be taken to make sure it receives colostrum or colostrum substitute during its first few hours.

Symptoms

• Mare does not produce colostrum
• Foal is underweight and weak
• Soft, droopy ears and lips
• Fine, downy haircoat
• Legs not fully developed and become crooked or bowed when foal attempts to stand
• Foal's knees and hocks are mostly soft cartilage

Causes

The cause of most premature foal deliveries is placental infection. Most placental infections are caused by bacteria ascending through the vagina and entering the uterus.

As the placenta is invaded by bacteria, it pulls away from the uterine lining. This detachment causes less oxygen to be passed on to the foal, which retards the foal's growth and adversely affects its ability to survive.

Prevention

In spite of the deaths and monetary costs connected with premature foals, little progress has been made in understanding how premature deliveries can be prevented or treated in a practical and economical way.

Treatment

An experienced, knowledgeable veterinarian should be called immediately when a foal is delivered prematurely. The premature foal will need special attention from the moment of delivery until several weeks or months have passed, depending on how mild or serious the medical and developmental complications are.

Neonatal diseases and complications range from minor to very severe. Premature foals often suffer from respiratory and cardiac problems and complications with immature bone structure and infections.

After the delivery, the placenta should be examined carefully by the attending veterinarian and should be submitted to a diagnostic laboratory for histopathological evaluation. If there are any irregularities in the placenta, this analysis will enable the veterinarian to be proactive in treating infections and other problems.

Making sure the foal receives the immunization advantages of colostrum during the first few hours after delivery is essential. If the mare does not produce colostrum, a substitute colostrum should be obtained and given.

If the mare does produce colostrum, but the foal is too weak or unstable to nurse, the milk containing the colostrum can be fed using a bottle prepared for the purpose.

Intravenous fluids and antibiotics to restore hydration and treat for infection are important. Treating a neonatal foal is an intensive process that involves around-the-clock care. The administration of IV fluids, parental nutrition, antibiotics, oxygen, cardiac monitoring, and other support therapy will be determined by the premature foal's condition and response to treatment.

Under-developed bones, especially those of the legs, will need to be evaluated by an orthopedic specialist. Soft bones will need to be put in casts or splinted so they develop in a straight, supported position. The foal may need to be sedated while this is being done.

If the foal has an infection in the navel, which sometimes happens, antibiotics may be used. Surgery to remove the infected navel structures may be necessary because the navel is a direct passageway to the bloodstream, allowing bacteria to spread to other areas, including the joints, with extremely serious consequences.

The prognosis for a healthy, productive future becomes better with each day the foal survives.