The Oregon Department of Agriculture said over the past two weeks, they have received six confirmed reports of West Nile Virus in horses, with another suspected case under investigation. The cases are spread out across the state, in Umatilla, Malheur, and Klamath counties. ODA says none of the infected horses were recently vaccinated against West Nile. Oregon is the most recent state to report a sudden increase in West Nile Virus cases, with similar reports coming from Washington, Idaho, and California. Because of that, ODA is advising all horse owners to have their animals vaccinated annually.
In addition ODA says a case of Equine Herpesvirus Myeloencephalopathy [EHV-1] has been reported in two horse, and suspected in another, with two others expose to the virus in Linn County. Two of the affected horses have been euthanized. A preliminary investigation shows none of the five horses have been moved off the farm or in contact with other horses in the past four weeks. ODA has placed the farm under quarantine.
EHV-1 is highly contagious. While there are no known exposures linked to the Linn County farm, the ODA recommends that horse owners concerned about exposure monitor their horse’s temperature and contact their veterinarian if a fever or clinical signs develop. EHV-1 testing is generally not advised in asymptomatic horses. More information is available from Equine Disease Communication Center (EDCC).
West Nile Virus and EHV-1 are both reportable diseases in Oregon. Veterinarians must report suspected cases to the Oregon State Veterinarian by calling (503) 986-4680.
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