EHV-1 Diagnosed in California Barrel Racing Horse stock photo © Dave Lundy

EHV-1 Diagnosed in California Barrel Racing Horse

California officials report a Quarter Horse gelding tested positive for the non-neuropathogenic strain of the equine herpes virus (EHV-1).

The barrel racer, originating from San Luis Obispo County, displayed symptoms including mild hind limb ataxia. The 7-year-old is being cared for by veterinarians in Santa Barbara. An epidemiological investigation has been initiated, and owners with potentially exposed horses will be contacted, according to the state.

EHV-1 may lie dormant for long periods of time and then re-activate during a period of stress, which can result in clinical disease.

The incubation period of EHV-1 is 1-10 days and signs are typically seen within 1-3 days. Viral shedding of the virus occurs for 7-10 days, but can occur up to 28 days from the onset of signs.
Symptoms may include fever, decreased coordination, nasal discharge, urine dribbling, loss of tail tone, hind limb weakness, leaning against a wall or fence to maintain balance, lethargy, and the inability to rise. While there is no cure, the symptoms of the disease may be treatable.
Veterinarians recommend using proper bio-security measures when attending equine events to help protect your horses from the potential spread of any illness:

· Limit horse-to-horse contact.

· Limit horse-to-human-to-horse contact.

· Avoid use of communal water sources.

· Avoid sharing of equipment unless thoroughly cleaned and disinfected between uses.

· Monitor your horse for clinical signs of disease and report any temperature over 102°F to a veterinarian.

Last week, a Virginia horse was euthanized due to neurologic EHV-1.