Horse at boarding school in Pennsylvania positive for equine neurological herpesvirus
A horse at a boarding school in Bucks County, Pennsylvania tested positive for the neurological form of equine herpesvirus type 1 (EHV-1, also known as equine herpesvirus myeloencephalopathy, or EHM). The horse presented with a mild fever, followed a few days later by severe neurological signs, prompting testing and euthanasia. The horse was not a new resident at the undisclosed facility, and all other horses on the property are under quarantine and being monitored for signs of illness.
EDCC Health Watch is an equine network marketing program that uses information from the Equine Disease Communication Center (EDCC) to create and distribute verified equine disease reports. EDCC is an independent, not-for-profit organization that is supported by industry donations to provide open access to infectious disease information.
Herpesvirus is highly contagious in horses and can cause a variety of equine ailments including rhinopneumonia (a respiratory disease commonly found in young horses), abortion in broodmares, and EHM.
In many horses, the first or only sign of EHV-1 infection is fever, which may go unnoticed. In addition to fever, other common signs of EHV-1 infection in young horses include coughing, loss of appetite, depression, and runny nose. Pregnant mares usually show no signs of infection before aborting, and abortions usually occur late in gestation (about eight months), but can be earlier. Abortions can occur two weeks to several months after EHV-1 infection.
Horses with EHM usually have a fever early in the disease and may show signs of respiratory infection. A few days later, neurological signs such as ataxia (incoordination), weakness or paralysis of the fore and hind limbs, retention and drooling of urine, loss of tail tone and recumbency (inability to stand up) develop.
Herpesvirus is easily transmitted nose-to-nose or close contact with an infectious horse; sharing contaminated equipment, including mouthpieces, buckets and towels; or the clothing, hands or equipment of people who have recently come into contact with an infectious horse. Routine biosecurity measures, including basic hygiene and cleaning and disinfection practices, should be in place at all times to help prevent the spread of disease.
Current EHV-1 vaccines may reduce viral shedding but do not protect against the neurological form of the disease. Implementing routine biosecurity practices is the best way to minimize viral spread, and the best method of disease control is disease prevention.