Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Equine Proliferative Enteropathy, EPE

Synonyms: Lawsonia Intracellularis, Proliferative Ileitis, Intestinal Adenomatosis


This is a recently recognized bacterial infection often found in growing horses, usually under a year of age. It is a well known disease in pigs, and affects a variety of other species. It is found worldwide.

This bacteria affects the small intestine, which becomes chronically thickened and inflamed. This causes decreased digestion and absorption of nutrients.Affected foals tend to grow poorly, have poor body condition, have a pot-bellied appearance and rough coated.

Parasitism (worm load) or stress of weaning may predispose horses to developing this condition. The route of infection in horses is currently unknown, but it is believed that horses may be infected from ingesting contaminated feed or water or feces from an infected animal.

Treatment is with appropriate antibiotics. Many antibiotics are not effective against this bacteria and disease will continue in the face of treatment.

There is current research regarding the efficacy of a vaccine.

my vet's role


Diagnostics Used

These are tests that might be helpful to make this diagnosis or further characterize the condition.

Very Common
Less Common
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Fair to good with prompt treatment. Treated foals usually survive but may be stunted compared to their herd mates. Stresses that may bring on or worsen the disease are weaning and overcrowding.

my role


I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
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Questions To Ask Your Vet:
  • What is the latest research on diagnosis, treatment & prevention?
  • How can I manage my growing horses to minimize the incidence of this condition?

This disease is considered permanently established (endemic) on certain properties, and returns year after year. In this case, talk to your vet about monitoring young horses in order to provide early diagnosis and treatment.

There is research regarding the efficacy of a vaccine but currently a vaccine is not available.

Related References:

Higgins AJ, Snyder JR eds. The Equine Manual. 2nd Ed. Edinburgh: Elsevier Saunders 2006.

Author: Doug Thal DVM Dipl. ABVP