The Department of Agriculture Friday placed a quarantine on horses in an equine pleasure riding stable in Doylestown, Bucks County, after two horses at the stable developed signs consistent with equine herpesvirus myeloencephalopathy (EHM) and subsequently tested positive for equine herpesvirus type 1 (EHV-1) on December 22, 2015.
Two additional horses were euthanized on December 24 and 31, respectively, after presenting similar clinical signs. They also tested positive for EHV-1. Other horses at various locations throughout Pennsylvania with suspect clinical signs have been tested but there have been no positive results.
In tracing back the positive horses, Pennsylvania animal health officials determined that one of the first two horses euthanized had participated in a horse show in Hidden River, N. J. Extensive tracing activity conducted by New Jersey animal health officials identified no new suspect horses.
Clinical signs of the disease can range from respiratory to neurological impairment. In most situations, the disease is only mildly contagious and some horses make a full recovery. In this case the virus strain involved has caused unusually severe disease and high viral loads.
There is no threat to human health from Equine Herpesvirus.
The riding stable and resident horses will remain under quarantine for at least 21 days. The quarantine can be lifted at some point after that three-week period depending on the course of the disease. Strict sanitary and biosecurity standards will be enforced throughout the quarantine.
To date four horses have been euthanized as a result of EHM. An additional eight horses have less severe clinical signs and some have shown improvement. All horses at the stable are being closely monitored and are receiving comprehensive veterinary care.
Department officials have noted the quarantined facility’s consistent and complete compliance with sanitation and biosecurity measures to help ensure the safety of the resident horses.Horse owners with concerns may contact the department’s Bureau of Animal Health and Diagnostic Services at 717-772-2852.