Four Washington horses were positively diagnosed for the non-neuropathogenic strain of equine herpes virus according to the Washington State Department of Agriculture.
Two of the horses attended the HITS Desert Circuit in Thermal, Calif., from March 5-11.
According to the Pilchuck Veterinary Hospital, Snohomish, Wash., the horses reside in two different facilities, both of which are following quarantine procedures.
Additionally, on March 30 the California Department of Food and Agriculture confirmed a new case of EHV-1 in Los Angeles County. The mare did not attend the HITS show, but other horses in the same facility did. She is quarantined and under veterinary care.
Pilchuck recommended owners of horses that attended the Thermal shows take their horses’ temperatures twice daily and monitor for any respiratory or neurological symptoms such as limb weakness. Also, avoid transporting those horses and minimize contact with any new horses.
In March, three California horses were diagnosed with the same strain after competing at HITS. The non-neuropathogenic strain of EHV-1 is responsible for respiratory cases, but some horses with the non-neuropathogenic strain can display neurologic signs.