EHV-1 Confirmed in Ontario

One horse residing in Wellington County, Ontario, Canada, has been euthanized after testing positive for the neurologic form of equine herpesvirus-1 (EHV-1), according to a Jan. 19 veterinary alert from the Ontario Ministry of Agriculture, Food, and Rural Affairs.

According to the alert, the horse began exhibiting severe neurologic signs in early January. A subsequent blood test confirmed the animal was EHV-1-positive. The horse was later euthanized when his condition deteriorated, the alert said. It was not reported if any other horses were exposed to the EHV-1-positive animal.

The alert also noted that another horse on a nearby farm was euthanized in late December after exhibiting neurologic signs, however no samples were collected to determine if the horse was EHV-1 positive.

There was just one laboratory-confirmed case of neurologic EHV-1 reported in Ontario in 2011, the alert said.

Although it's not transmissible to humans, EHV-1 is highly contagious among horses and camelids, and it is generally passed from horse to horse via aerosol transmission (when affected animals sneeze/cough) and contact with nasal secretions. The disease can cause a variety of ailments in equines, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (EHM, the neurologic form).

Myeloencephalopathy is characterized by fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence. Should a horse with potential EHV-1 exposure display any of the aforementioned clinical signs, a veterinarian should be called to obtain samples and test for the disease.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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