Equine Proliferative Enteropathy Caused by Lawsonia

Equine proliferative enteropathy is an emerging disease caused by the Lawsonia intracellularis bacterium. It is seen most commonly in recently weaned foals but can affect adult horses.

Common signs are fever, lethargy, loss of appetite, swelling of the legs and along the lower abdomen, colic, and diarrhea, though not all signs may be present. Because this disease has signs that resemble those of other gastrointestinal ailments, diagnosis can be difficult. After excluding other diseases, diagnosis is based on the presence of low blood protein levels and detection of the specific bacteria in the feces, although the bacteria may not be found in subclinical cases or in animals where the disease has been established for a long time.

Another diagnostic marker is thickening of segments of the small intestinal wall, though ultrasonography is not completely reliable in showing this development. Treatment with antimicrobials is usually successful, especially if begun early in the course of the disease.