Two horses contracted equine herpesvirus-1 after showing at the HITS Desert Circuit in Thermal, Calif., according to the California Department of Food and Agriculture.
On March 14, a gelding displaying hind leg ataxia in Monterey County tested positive for the non-neuropathogenic strain of EHV-1.
A second gelding in San Diego County tested positive for the same strain of EHV-1 on March 15 following similar symptoms. Both horses are in quarantine under veterinary care. This strain of virus is responsible for the more common respiratory EHV-1 cases, but a small percentage of non-neuropathogenic EHV-1 infected horses can display neurologic signs and are classified as equine herpes myeloencephalopathy cases.
The horses participated in the HITS horse show, and the CDFA recommends any horses that attended the event be closely monitored with twice daily temperature readings and quarantined.
Duncan Peters, MS, DVM, show veterinarian for HITS, said all the show veterinarians were well prepared for a potential outbreak with instructions to offer testing to any horse with a fever or any signs of EHV-1. “There was no reluctancy to test,” he said, noting that veterinarians were told to “not be shy” about testing.
Peters, who is the director of the Sport Horse division at the Hagyard Medical Institute in Lexington, Ky., said he has been in contact with the FEI show veterinarian in Florida to discuss the results of the tests from Thermal with the understanding that many horses will be traveling to Florida to continue competing.
“I don’t feel there’s any more risk than coming in from locally,” Peters said.
Peters emphasized that the CDFA website has the most accurate and up-to-date information, and people should frequent their local and state websites to stay informed.