A common cause of diarrhea in foals less than six months old.

UC Davis Center for Equine Health

Equine rotavirus damages the lining of the intestines, inhibiting digestion and absorption of food. It is one of the most common causes of diarrhea in foals less than six months of age. Foals become infected when they ingest materials or lick surfaces contaminated with infected feces.

Clinical signs of equine rotavirus infection can include diarrhea, lethargy, anorexia, reluctance to nurse, and distended abdomens. Infected foals may shed the virus in their feces for up to 10 days, and asymptomatic horses are capable of shedding the virus for up to eight months.

A diagnosis of equine rotavirus is made by virus identification through enzyme linked immunosorbent assay (ELISA) or reverse transcription polymerase chain reaction (RT-PCR) assays.

Treatment is primarily supportive and may include intravenous (IV) fluids, gastrointestinal protectants, and probiotics. Early detection and treatment of affected foals often lead to rapid recovery.

To prevent infection, pregnant mares can be vaccinated to increase their foals’ antibodies to the virus.

Sick foals are highly contagious and should be separated from other foals on the property. Staff who handle infected foals should adhere to strict biosecurity protocols. Since the virus can persist in the environment, do not spread manure from infected horses on pastures.

Related: What Are You Vaccinating Your Horse Against?

Related: Signs Cryptosporidiosis in Horses

Printed with the kind permission of the UC Davis Center for Equine Health. The UC Davis Center for Equine Health is dedicated to advancing the health, welfare, performance and veterinary care of horses through research, education and public service.