Page 67 - December 2017

Intravenous fluid therapy with the appropriate electrolytes is the most important part of treatment of foal diarrhea.
attention is imperative. A cause of diarrhea is not diagnosed in approximately 55% of cases of foal diarrhea, suggesting that the available tests are accompanied by many false negatives or that additional unknown causes exist.
TreaTmenT
Intravenous fluid therapy with the appro- priate electrolytes is the most important part of treatment of foal diarrhea. In severe cases when fluid losses and shock are severe, hospitaliza- tion for continuous fluid therapy is imperative. Repeated blood chemistry assessment is neces- sary to assure that electrolytes are supple- mented sufficiently, as electrolyte loss can be life threatening. Medications for treatment
of shock, including plasma transfusion, are needed in severely diseased foals. Medications that reduce the severity of the diarrhea (kaolin, pepto bismol, and loperamide) are sometimes used. These drugs may reduce the severity of fluid losses, but do not accelerate intestinal healing. Di-tri-octahedryl smectite (Biosponge) is one medication that reduces the water content of the stool and also absorbs some
of the toxins that may damage the intestinal wall. Infectious agents can sometimes be absorbed into the bloodstream, resulting in septicemia, and cause complications to other body systems such as the kidneys, lung and heart. Such cases require intensive monitor-
ing and treatment. Pneumonia and joint or bone infections are possible complications. Antibiotic therapy is sometimes prescribed to prevent or treat these complications. Gastric ulceration is another possible complication of diarrheal disease that can reduce nursing and cause colic. Foals with severe diarrhea that will not nurse may require feeding through a tube. Electrolyte or milk supplementation should
not be forced by syringe into the mouth of a foal due to the risk of aspiration pneumonia. Anthelmintics are chosen in cases of parasitism
and metronidazole is a specific antimicrobial often used in clostridial infections.
Careful caregiver monitoring is the key
to successful management of foal diarrhea. Differentiation between foals with nonin- fectious diarrhea (foal heat and nutritional diarrhea) and infectious diarrhea can be made by observation of nursing behavior, strength, severity of diarrhea, and general attitude and by measuring body temperature. Foals with infectious diarrhea can develop dehydration and shock very quickly and need veterinary attention for administration of fluids and elec- trolytes, antibiotics, and other forms of therapy. Foals less than three days old, body tempera- ture fever greater than 101 degrees F, decreased nursing frequency, reduced activity, or profuse protracted diarrhea should receive immediate veterinary attention. If the foal is older, has mild diarrhea and is bright, active, alert, and nursing, with a body temperature less than 101 degrees F, careful monitoring should continue until the diarrhea abates. In addition, the foal’s rump should be cleaned at least daily and a bar- rier ointment applied (e. g. zinc oxide).
PrevenTion and ConTrol
There are some preventative strategies that may reduce the incidence of foal diarrhea on a farm. Reducing the stocking density of horses
on the farm is important to reduce the numbers of infectious organisms shed into the environ- ment. Foals should be segregated according
to age to reduce the exposure of younger foals to organisms shed by older foals and adults other than their own mares. There are vaccines available for rotavirus to administer to mares
to increase the rotavirus antibody available in colostrum. However, the efficacy of this strat- egy is uncertain. Adequate immunity is vital to young foals to prevent or reduce the severity of illness. Transfer of antibody from the mare via colostrum at birth is vital to the health of foals. Foals should be tested within 24 hours of birth by a veterinarian to assure adequate colostrum ingestion. Products are available which contain specific immunoglobulins (produced in eggs) against Salmonella, E. coli, Clostridium, Rotavirus, Coronavirus and Lawsonia. These products are designed to provide additional antibodies to help foals combat exposure to these organisms. These products have not been evaluated by the USDA and efficacy has not been proven.
Prebiotics and probiotics are nutritional supplements commonly used to help prevent or treat infectious diarrhea in people. Their usage in horses has not been adequately studied. Probiotics are “good bacteria and yeast” that colonize the intestinal tract to
Treatment is most effective when initiated in the early stages of the disease, so foals should be monitored closely for changes in behavior and increases in body temperature.
Transfer of antibody from the mare via colostrum at birth is vital to the health of foals, who should be tested within 24 hours of birth by a veterinarian to assure adequate colostrum ingestion.
SPEEDHORSE, December 2017 65
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