Two new cases of Equine Herpes Virus have been identified in Montana. A 6-year-old mare in Gallatin County has tested positive for Equine Herpes Virus (EHV-1), but is not related to a case in Flathead County reported late last week.
The two cases of EVH-1 confirmed in Montana appear to be the less virulent wild strain of the disease and so far no other horses appear to be affected.
"We have another case of EHV-1, but let me stress that there is no connection to the earlier case," said assistant state veterinarian Dr. Tahnee Szymanski. "Fortunately, the Gallatin County case, like the Flathead case, appears to be an isolated event."
The infected horse arrived in Montana three weeks ago from southern California. The horse began showing clinical signs of the virus last week; test results received Saturday morning confirmed presence of the virus.
The horse is housed at a boarding and training facility, which is currently under quarantine, in Gallatin County. An encouraging sign, Syzmanski said, is that none of the other horses at the facility have shown any clinical signs of contracting the virus.
"The manager and trainers at the facility has been great to work with, and are letting all of their clients know about the incident," Szymanski said.
EHV-1 is naturally occurring in equine populations and may cause respiratory disease, abortion in mares, neonatal foal death, and/or neurologic disease. There are two types of the virus responsible for outbreaks in the U.S. - the neuropathogenic form, and the wild type. The horse in Gallatin County, as well as the horse in Flathead County, appear to have been infected with the less virulent wild type.
Please contact your veterinarian if you suspect your horse may be affected with EHV-1, or with any specific questions about your horse. You may also address questions to Dr. Tahnee Szymanski tszymanski@mt.gov; or call 406-444-2043.
Read more about EHV-1 and How to Prevent It