Foals are most susceptible to viral diarrheas during the neonatal, perinatal, and suckling periods by virtue of being immunologically naive. Clinical signs of disease have been reported in foals less than 6 months old, and most often in foals 3 months of age or less. Signs include diarrhea, lethargy, anorexia, and abdominal distention. A three year study of horse farms in Kentucky during the 1980s noted that rotavirus was the most common cause of diarrhea in foals. Rotavirus is species-specific (which means no other animal other than a horse can contact this disease), and has an incubation period of 1 to 2 days. Foals infected with rotavirus may shed the virus for up 10 days. Some horses may shed the virus asymptomatically for up to 8 months. Diagnosis requires detection of the virus in feces. Our laboratory can perform this diagnostic test.
Even though rotavirus is species specific we suggest precautionary measures be taken to reduce the risk of infection to other horses or people in contact with other horse.
¨ Ensure that other foals do not come in contact with manure from this horse. This may mean keeping the foal in a separate paddock, cleaning its stall with separate or disinfected tools, and properly disposing of the manure for two weeks.
¨ Wear disposable gloves when working with the horse. Carefully wash your hands when you are finished.
Prevention of this disease includes proper hygiene and the use of phenolic disinfectants (Tek-Trol, Biophene, Environ and Stroke-1), because bleach is ineffective against rotavirus. A commercial vaccine is currently available for use in mares before foaling to help increase the colostral antibodies. It has been noted that foals from vaccinated mares can still become infected with rotavirus, although the clinical signs may be attenuated.
Hagyard Equine Medical Institute has one of the highest equine caseloads in the world. Because we run a state-ofthe-art hospital, we are dedicated to providing the best veterinary care possible to our patients. As part of our veterinary services, we run an infection control program to control and prevent infections in our patients during hospitalization. The main goal of this program is to develop an early warning system for detection of disease causing organisms and help prevent the potential spread of disease. This surveillance system entails performing bacterial cultures on samples from patients. A primary concern is for infectious organisms passed in manure (eg. salmonella, rotavirus and clostridium).