Second Quebec Horse Euthanized Due to EHV-1

Second Quebec Horse Euthanized Due to EHV-1

The neurologic EHV-1 virus

Photo: George P. Allen, PhD

A second horse has died in the Canadian outbreak of the neurologic equine herpesvirus-1 (EHV-1), but currently no horses are showing signs of the disease, according to a spokesperson for the affected site.

A 14-year-old Quarter Horse gelding was euthanized after developing severe ataxia (incoordination) one week after the index case, a 12-year-old Canadian Horse mare, was euthanized, said Laurie Michaud, an instructor at that affected facility, Bédard Quarter Horses. Another horse that had been symptomatic has since recovered.

The quarantine at the Chicoutimi, Quebec farm—which is not imposed by the Canadian government—will remain in place at least another 26 days, Michaud said. No horses have had fevers or shown neurologic signs of disease in the past 16 days, and horses continue to be checked twice daily for rectal temperature and signs of ataxia, Michaud said.

None of the horses in the affected stable had competed in Florida, but they had been to national shows with other horses that could have been in international competitions, including Florida, Michaud said. The source of the outbreak has still not been determined.

Several equestrian events in the region have been canceled due to the outbreak, and some horses have become sick with similar symptoms but without an official diagnosis of herpesvirus, according to Michaud. “The disease has caused a bit of a panic in the region, which is causing some rumors to start spreading about the progression of the disease,” she said. However, presently it appears that no other cases have been confirmed.

Canada does not require notification of EHV-1, so alleged reports of other diseased horses cannot always be verified.

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

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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