A Santa Barbara County, Calif., gelding has tested positive for non-neuropathogenic equine herpesvirus-1 (EHV-1), the California Department of Food and Agriculture (CDFA) reported March 25.

"A Welsh Cross gelding in Santa Barbara County displaying neurologic signs on March 20, 2013, has been confirmed positive for the non-neuropathogenic strain of EHV-1," the CDFA reported in a statement on their website. "This strain of virus is responsible for the more common respiratory EHV-1 cases. A small percentage of non-neuropathogenic EHV-1 infected horses can display neurologic signs and are classified as equine herpes myeloencephalopathy cases which are a reportable condition in California.

On March 19, the CDFA reported that a Warmblood stallion from San Diego County had also tested positive for the non-neuropathogenic strain of the virus.

"CDFA’s epidemiologic investigation indicates the Welsh Cross gelding and the Warmblood stallion both participated in the HITS (Horse Shows in the Sun) event in Thermal, Calif.," the CDFA’s statement continued. "The Welsh Cross gelding departed Permanent Barn 2 on March 10 and the Warmblood stallion departed Tent 29 on March 15. Both confirmed positive horses have been quarantined and are under veterinary care. Potentially exposed horses to EHV-1 are recommended to be isolated and temperatures monitored twice daily for 14 days post potential exposure date."

Equine herpesvirus-1 is highly contagious among horses and camelids and is generally spread via aerosol transmission (when infected animals sneeze and cough) and through contact with nasal secretions from infected animals. The disease can cause a variety of problems in horses, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and EHM.

Fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence are signs of EHM. If a horse that has possibly been exposed to EHV-1 begins to display any of the aforementioned signs, call your veterinarian immediately.