At least 10 horses have died or have been euthanized at the University of Findlay (UF) in Findlay, Ohio, after battling a respiratory and neurologic illness. Preliminary polymerase chain reaction (PCR) tests completed on tissue samples from affected horses by the Ohio Department of Agriculture’s (ODA) Animal Disease Diagnostic Laboratory this morning came back as “presumptive positive” for equine herpesvirus type-1 (EHV-1). Officials from the veterinary services department at the University of Findlay and epidemiologists and scientists from The Ohio State University (OSU) are working together today to treat at least 11 affected horses with supportive care and determine the source of infection. The presumptive findings from the PCR tests will be verified by gene sequence analysis, with assistance from Ohio State. The results will be available from ODA in two to three days.

The EHV-1 organism can cause three different forms of disease, including rhinopneumonitis (a respiratory disease of mostly young horses), abortions in pregnant mares, and a neurologic disease. Officials believe this strain, if confirmed as EHV-1, could be one that combines the respiratory and neurologic clinical signs. There are at least seven other strains of equine herpesviruses, named in order of their discovery. (See article #32 at www.TheHorse.com for more on herpesviruses.) The neurologic form of EHV-1 often is survivable with supportive care, but unfortunately once a horse is recumbent, it is difficult to nurse the horse back to health