Montana reports first equine herpes virus case from outbreak, WSU reopens veterinary hospital to equine patients

National Report

— While veterinary officials say the equine herpes virus (EHV-1) outbreak from a Utah cutting horse competition is on the decline, Montana confirmed its first primary case on June 11.

“We have a non-clinical EHV-1 positive case associated with the National Cutting Horse Association (NCHA) Western National Championships in Ogden, Utah, April 30-May 8, 2011,” says Dr. Marty Zaluski, Montana's state veterinarian. “Fortunately, this horse not only remains healthy, but has been separated from other horses since returning from Ogden."

The horse, a 13-year-old gelding, was exposed to the virus at the NCHA event, according to Montana livestock officials. The horse has been isolated from other horses on the premises since returning to its home. The horse has also been routinely tested by its owners.

Just days before the case in Montana was confirmed, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) released a report touting that the outbreak was on the decline. In that same week, only three new secondary or tertiary cases had been confirmed, APHIS reports.

As of June 8, there were a total of 88 confirmed cases of EHV-1/equine herpesvirus myeloencephalopathy (EHM). EHV-1 primary exposures totaled 32, and EHM primary cases totaled 26, compared to 23 EHV-1 secondary cases and seven EHM secondary cases.

In a related event, Washington State University's Veterinary Teaching Hospital, which closed its doors to non-emergency equine cases in order to prevent the spread of the virus, resumed normal operations.

"Reopening is slightly ahead of schedule because there have been no new cases of EHV-1 in Washington for more than two weeks," the university reports. The WSU veterinary hospital underwent a sterilization process that included disinfecting everything from the floors to the ceilings and everything else between. "Stall mats were removed as were any porous surfaces on doors or dividers," the veterinary school reports.

The effort required a crew of 15, including 10 temporary hires.

As an added precaution, WSU says it will institute a new screening process for each referral or private admission patient. The hospital will rank each patient according to its risk for developing active disease from an EHV-1 infection.