Foal Pediatrics

...and on the eighth day God created the horse in perfect image, to romp, graze, gallop, play and make manure wherever it darn well pleases, in divine grace.

The foal is especially susceptible to a number of diseases as a growing neonate. Older horses can also get many of the same diseases, but they do not pose the threat to life or health as they do when the foal is a baby.

Symptoms of illness are weakness, eye/nasal discharge, lameness, coughing, diarrhea, swollen joints, listlessness and a lack of vigorous nursing. Some of the most common foal ailments are rotavirus infection, tetanus, foal septicemia, equine influenza and rhinopneumonitis. (1)

Fever in a foal is an emergency, call the Vet. Normal temperature in the foal is 99 to 102F.

Of serious importance is the ingestion of the dam’s first milk or colostrum by the baby. Horses do not have protection through passage of immunoglobulins and antibodies from the placenta. Many species , man included, receive protection of antibodies from the placenta while still inside the mother. A baby horse does not have any immunoglobulins and can only acquire them by drinking its mother’s milk within the first 18-24 hours after being born.

Immediately upon being born, the cells of the intestinal lining, by way of special adaption, absorb antibodies through the mucosal barrier and they enter the bloodstream of the neonate. At the end of 24 hours, the barrier closes and the antibodies can no longer be absorbed.

It is very important that the baby receive the colostrum in its mother’s milk. The milk of the dam also contains high fat, minerals, protein and vitamins. Along with the immunoglobulin antibodies, there are other immune substances (IgG) which protect the baby. The problem is called FPT and it is the Failure of Passive Transfer of these immunoglobulins and it is the single most important cause of neonatal infection and death in the first week of life. (2)

FPT can happen for any number of reasons, including premature lactation of the dam prior to delivery, death of the dam, insufficient production of colostrum due to maternal illness or advanced age, rejection by the dam, delay in suckling by the foal due to illness or weakness.

Any mare dripping milk prior to delivery is losing valuable colostrum. The owner should be on alert that there is the definite possibility of complete or partial FPT. This milk should be collected and stored in the deep freeze, to be given by bottle to the foal after delivery.

It requires several pints of colostrum to provide adequate blood levels of IgG in the foal. If there is a question as to how much or little the foal may have ingested, call the Vet. A quick blood test (Cite) can be run to note IgG when the foal is 12 hours old to determine if adequate colostrum has been ingested. (3)

It is obvious that the foal needs help if the dam is dead or it has failed to nurse. When colostrum deficiency is evident, replacement colostrum is administered immediately. It must be within the first 18 hours of life to be a success.

Cow’s colostrum, freeze-dried IgG or equine blood plasma can be given to the foal if the dam’s colostrum is unavailable. The best method to insure that the foal ingests the substitute is by a nursing bottle, not a stomach tube.

The treatment of FPT is finished when 1 to 2 liters of pooled equine plasma are injected into the vein after a 24 hour time frame. The levels of circulating IgG, determined by blood test will help with the decision to treat the foal, and the Vet will determine how much plasma to give.

Most breeding farms have a colostrum bank, keeping it frozen in event of emergency. The Vet is always helpful in locating a postpartum mare for the backyard Horseman, if need be.

The most common cause of severe illness and death in a foal is septicemia. It is rapidly progressive and often fatal, affecting foals 7 days old or younger. It contains a number of different bacterial pathogens rather that one specific bacterial infection.

FPT is the most significant factor in the development of foal septicemia. Other causes are stress of cold or wet surroundings, prematurity, overcrowding and complicated birthing. A foal that does not nurse within 2 to 3 hours, that does not stand up within 2 hours or shows signs of physical or behavioral abnormalities, is at risk of septicemia. (3)

Signs can appear at 2 to 4 days, followed by rapid decline. The early symptoms are reluctance to nurse (be alert for engorgement of the mare’s udder), lethargy and weakness. Watch for the foal to spend and unusual amount of time sleeping or lying on its side. Coughing and diarrhea can be an indication of early infection. By the time its joints are swollen or it has difficulty breathing, there is shock, convulsions and collapse. Prognosis is poor. (4)

Sleepy foal syndrome or Actinobacillosis is another cause of foal septicemia. Symptoms appear during the first 48 hours of life, but sudden death can occur as early as 6 hours after birth. (5)

The bacteria can sometimes be present in the reproductive systems of seemingly healthy mares and this may be why some foals appear to be infected at birth. Other foals appear to contract the bacteria through ingestion.

Sick foals have difficulty standing and nursing, can have diarrhea and are extremely weak. They sleep all the time and can even slip into a coma.

Navel ill or umbilical infection occurs because of bacterial infection of the umbilical array, which include the urachus, the artery and the vein. It can be picked up while foaling or by contamination of the stump while it heals. Usually streptococcus is involved, but there can be a number of other bacteria. (6)

Signs include a puslike discharge, with the naval stump being swollen, tender and hot. The foal quits nursing and loses interest in its surroundings.

When it becomes septicemic, the bacteria enter the bloodstream through the umbilical vessels and spread to the joints, liver and other places. The foal becomes depressed and goes into shock, dying within 12 to 24 hours. Another route the disease may take is that the foal does not develop septicemia but instead shows signs of joint ill.

Joint ill or septic arthritis and osteomyelitis is a bacterial infection that enters the bloodstream, bones and synovial membranes of the joint. Remember that any type of foal infection that causes septicemia can cause joint ill. Navel ill is the predisposing cause in 25 percent of cases. (7)

Bacteria enter through the respiratory or digestive tracts and the foal will show a sudden lameness along with hot, swollen joints and fever, 102- 104F, loss of appetite and listlessness.

Call the Vet. Analysis of joint fluid sent in for sensitivity testing and bacterial culture can confirm a diagnosis. Arthroscopy can help and ultrasonography can distinguish between infected fluid within a joint or an abscess around a joint. A series of x-rays are necessary to diagnose developing osteomyelitis. (8)

Tyzzer’s Disease is a rare and rapidly fatal disease caused by an infection of the liver, occurring in foals under 6 weeks of age. The bacteria is called Bacillus piliformis and it is not known how the disease is spread. (9)

Symptoms are seizures, diarrhea, high fever and collapse, all occurring within a matter of hours. Mares may be carriers and the disease progresses so rapidly that the diagnosis is made at autopsy.

Foal Heat Diarrhea or 9-day diarrhea affects nearly all newborns. The argument occurs among Horsemen that the diarrhea happens when the mare enters her first heat cycle, due to hormones in the mother’s milk, but orphans also exhibit symptoms. Foals also eat manure, hay and grain and this may upset the flora in the foal’s digestive tract. This, too, also passes.

Rotavirus or Viral Enteritis is a highly contagious diarrhea occurring in foals up to 6 months old. It was once thought to be confined to Kentucky and the southeast U.S., but it is now worldwide. Annual springtime epidemics can infect 70 percent of foals on one farm. The virus is shed by way of infected manure and recovering foals. Transmission occurs through contaminated water, bedding, feed, grooming utensils or human hands. (10)

Diarrhea is serious in horses; call the Vet within 24 hours of onset if symptoms do not clear up.

Other foal diarrheas are nutritional, parasitic, protozoal (trichomonas and cryptosporidiosis) and bacterial (salmonellosis, clostridial, e.coli). (11)

These are very serious conditions; call the Vet.

Attentiveness is essential as are clean conditions and a good parasite control program. Work closely with an experienced Horseman and your Vet to prevent these often fatal diseases.

The aforementioned article is meant as a guideline and not Veterinary analysis. Always consult a qualified Vet if you suspect a problem with your mare and foal in the Pediatrics Department.

Praying to the rain gods, but not dancing, to the immortal words of Roy Rogers and Dale Evans, “Happy Trails to You.”

1-11:”Horse Owner’s Veterinary Handbook,” by Drs. Giffin and Gore