New veterinary lab offers PCR testing for equine respiratory virus

Equine Diagnostic Solutions (EDS), based in Lexington, Ky., is the latest laboratory to begin testing for equine rhinitis A virus (ERAV). EDS says requests for ERAV testing prompted the addition of the polymerase chain reaction (PCR) test.

EDS is the fourth U.S. lab to offer the test, following IDEXX Laboratories, the University of California-Davis and Cornell University.

ERAV affects both upper and lower airways in horses and may be spread by contact through nasal secretions and aerosol inhalation. The virus has been isolated from thoroughbred horses with acute respiratory disease in the United States, Canada, Australia, Japan and Europe and is thought to contribute to disease in these regions.

“ERAV should be something every veterinarian includes in differential diagnosis when it comes to respiratory disease,” says Rob Keene, DVM, field equine technical manager with Boehringer Ingelheim Vetmedica. “But it isn’t a disease that is necessarily at the forefront of practitioners’ minds in the United States.”

According to a 2012 study conducted by Keene and presented at the 2012 ACVIM Forum in New Orleans, 44 percent of all sampled horses exhibited serum-neutralizing antibodies to ERAV. In the same study, seroprevalence increased with age, with 9 percent of yearlings and 38 percent of 2-year-olds seropositive to ERAV.

“We decided to add the test due to demand from our customers,” says Dr. Jennifer Morrow, co-owner and lead scientist at EDS. “Really, it was a natural addition based on the requests we were receiving.”

Boehringer Ingelheim, manufacturer of an ERAV vaccine, says in a release that ERAV can be identified through both PCR testing of nasal swabs and urine, which demonstrates ERAV viral RNA present in the horse, and through serological testing, which shows antibodies to the disease. However, serological testing is only available at Cornell University.