Ontario agriculture officials confirm a horse has been euthanized after showing severe neurological signs of caused by equine herpes myelocencephalopathy (EHM). EHM is cause by the equine herpes virus (EHV-1).
Brain tissue from the euthanized horse tested positive for the neuropathogenic strain of EHV-1. The owner has placed the farm, located in the Regional Municipality of Waterloo, under a voluntary quarantine to reduce the risk of viral spread. No other horses are sick at the stable, according to officials.
Temperatures should be monitored for suspect animals twice a day for 14 -21 days. Infected horses may not show clinical signs, but still shed the virus. Neurological signs of the disease may include loss or balance, hind-limb weakness, recumbency, difficulty urinating, decreased tail tone and depression.
EHV-1 is spread by nose-to-nose or close contact with an infectious horse, by sharing contaminated equipment, or by the clothing, or hands of those working around the horse. Biosecurity measures are necessary.
EHV-1 vaccines may reduce viral shedding, but are not protective against the neurological form of the disease, according to veterinarians. Cases of EHM have been diagnosed in Texas, Virginia, Minnesota, Oklahoma, and New Jersey this month.