Foals Can Shed EPE Organisms to Uninfected Horses

Weanling foals that come down with equine proliferative enteropathy (EPE) will recover if they are treated properly, so owners should look for this emerging disease in sick foals, said Nicola Pusterla, DVM, PhD, Dipl. ACVIM, associate professor at the University of California, Davis, School of Veterinary Medicine.

Signs of disease include lethargy, weight loss, fever, loose stool, and peripheral edema (throat latch, sheath, distal limbs). "The prognosis is good if foals are treated specifically for EPE," he said. Treatment includes fluids, plasma, and antibiotics. In addition, make sure they get good nutrition.

Pusterla and his colleagues recently studied Lawsonia intracellularis, the bacteria that causes EPE. They wanted to know how the disease progresses and whether infected foals shed the organism and posed a threat to herd mates. They infected three foals withL. intracellularis and studied how the disease progressed (clinical signs, clinicopathological findings, antibody titer, and fecal shedding).

They found that the foals shed L. intracellularis. Therefore, infected foals should be separated from the rest of the heard because they might expose susceptible herd mates, according to Pusterla.

"The disease has two faces, a clinical presentation that is really easy to diagnose and a subclinical form, which goes together with transient blood work abnormalities (low albumin) and fecal shedding of L. intracellularis," he said.

Experts believe that young foals are protected from the disease while nursing because they get protective antibodies from the mare, but once they stop weaning, they become susceptible to the disease, and the stress of weaning puts them at risk.

"Young adults can also contract the disease, however, this is a rare event," he said.

At the moment, there is nothing owners can do to prevent infection, but researchers are looking for a vaccine, he said.

The study "Oral infection of weanling foals with an equine isolate of Lawsonia intracellularis, agent of equine proliferative enteropathy" was published online ahead of print in the March Journal of Veterinary Internal Medicine.

The abstract is available on PubMed.

About the Author

Marie Rosenthal, MS

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