Determining the Best Samples for EPE Testing

A recent study found that using rectal swab samples could be an alternative way to test for the Lawsonia intracellularis bacteria that causes equine proliferative enteropathy (EPE) if the foal has decreased or no fecal output.

EPE is an emerging intestinal disease found in weanlings. Because the disease occurs right around the time a foal is weaned, some veterinarians think it could be related to the stress of weaning and the loss of the protective substances found in the mare's milk. The number of EPE cases appears to increase yearly, according to Nicola Pusterla, DVM, PhD, Dipl. ACVIM, of the University of California, Davis. Affected foals usually suffer peripheral swelling, weight loss or slow growth, lethargy, loss of appetite, fever, colic, diarrhea, and low blood protein levels.

EPE testing includes blood work to measure blood-protein levels and polymerase chain reaction (PCR), which is molecular testing of fecal material.

"Researchers are looking at the most reliable sample material (feces versus rectal swab) for the PCR detection of Lawsonia," says Pusterla. "Based on the study, it looks like feces and rectal swabs have a similar accuracy at detecting Lawsonia shedding."

He added that the most accurate results came when both samples were submitted for testing, but admitted sending two samples would be too costly for most owners.

Since there is no vaccine approved for use in horses, identifying cases early and treating them is the best treatment method.

The study, "Comparison of feces versus rectal swabs for the molecular detection of Lawsonia intracellularis in foals with equine proliferative enteropathy," appeared in the September issue of the Journal of Veterinary Diagnostic Investigation.

The study can be found in PubMed.

About the Author

Marie Rosenthal, MS

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