Deadly Horse Disease Strikes Again

1/26 UPDATE: The Desert Sun is reporting that the NEHV-1 case in the Coachella Valley was located at the Empire Polo Club in Indio.

A deadly equine disease that struck just west of Wildomar has now hit Riverside County.

Tuesday afternoon, a Neuropathogenic Equine Herpes Virus -1 (NEHV-1) case was confirmed in the Coachella Valley, according to Steve Lyle, public affairs director for the California Department of Food and Agriculture.

The sick gelding displayed hind limb incoordination and urine dribbling. He became recumbent and was euthanized, according to Lyle.

Lyle said the CDFA has not released the name of the facility where the horse was located, but said the premises are under quarantine.

The case follows news that 15 horses at  in San Juan Capistrano have tested positive for the disease. but since that time four new cases have been found at the facility. Only one of the 15 horses there has shown neurologic signs, according to the CDFA.

The CDFA is not aware of any links between the Orange County and Riverside cases, but the situation is being closely monitored, Lyle said.

“It is a disease that presents a high level of concern,” Lyle said. “It’s a stressful prospect for horse owners.”

The disease is easily spread and currently there is no equine vaccine with a label claim for protection against the neuropathogenic strain of the virus, Lyle said.

Clinical signs of NEHV-1 include nasal discharge, incoordination, hindquarter weakness, recumbency, lethargy, urine dribbling and diminished tail tone. The prognosis for horses that test positive depends on the severity of signs and the period of recumbency, according to the CDFA.

The recent Southern California NEHV-1 outbreak was first detected Jan. 11 at the San Juan Capistrano facility, according to the CDFA. At press time, the Orange County and Riverside cases are the only confirmed positive NEHV-1 incidents in the region.

At the San Jan Capistrano facility, only the initial confirmed positive horse displayed neurologic signs and he is currently recovering, according to the CDFA. All other confirmed NEHV-1 positive horses displayed respiratory symptoms, limb edema and/or fever. However, one of the horses that tested positive was euthanized Jan. 18 after becoming recumbent. Necropsy results revealed the recumbency was likely unrelated to the NEHV-1 infection.

Last May, 400 horses were exposed to neuropathogenic strain of EHV-1 at the National Cutting Horse Association Western National Championship held in Ogden, Utah. Local horses were at the show. to read more about that incident. The CDFA reports that last year’s outbreak is unrelated to the current cases.

To keep abreast of the state's findings, click here.

To learn more about NEHV-1 and how you can protect your horses, contact your local equine veterinarian and check out the attached PDF file published by the California Department of Food and Agriculture.