Two cases of neurological disease in horses arising from Equine Herpes Virus-1 (EHV-1) infection have been reported, one in California and the other in Virginia.
The Virginia Department of Agriculture and Consumer Services confirmed last Thursday that a horse was euthanized on a farm in Prince William County due to neurologic disease.
Post-mortem test results confirmed that the horse was positive for the neurologic strain of EHV-1.
Authorities said the horse had not traveled off the farm recently.
No other horses on the farm have shown any signs of disease. All horses on the property will be monitored for 21 days for any signs of the disease. They are not permitted to leave the property during the monitoring period.
In California, a 7-year-old barrel-racing quarter horse gelding, originating from San Luis Obispo County, tested positive for the non-neuropathogenic strain of EHV-1.
This strain usually results in flu-like systems and respiratory illness. However, a small percentage of horses infected with the strain can display neurologic signs.
In this case, the horse had a mild lack of coordination in his hind limbs.
California agriculture authorities said the gelding was under veterinary care in Santa Barbara County and was recovering.
Staff have been working to contacting owners whose horses may have been potentially exposed.