ONTARIO – There have been three confirmed strangles cases in Ontario equines so far this month.
The Ontario Ministry of Agricultural, Food and Agribusiness (OMAFA) reported one case in Grey County and one in Halton Region on July 2, and a third in Kawartha Lakes on July 10.
Strangles is a highly contagious equine respiratory disease, also known as equine distemper, that can cause high fevers, inappetence, coughing, thick white nasal discharge and severely swollen lymph nodes in horses’ heads and necks.
It gets its name because the lymph nodes can swell so severely that they are said to “strangle” the horse, restricting breathing.
The Kawartha Lakes horse is a six-year-old quarter horse mare that developed a swollen lymph node that tested positive for strangles.
The Grey County horse is a 12-year-old paint gelding that OMAFA stated tested positive for strangles after developing “classic signs of strangles two weeks after being purchased from someone who buys and sells horses as their occupation.
“The horse also stopped over at a sales barn in [Waterloo Region] for 48 hours prior to arriving at its new location,” officials continue.
In Halton a 35-year-old gelding pony with “other significant health issues” developed an abscess under his jaw after receiving immune modulating medication.
The abscess tested positive for strangles, and “the pony was euthanized due to its declining health,” OMAFA officials state.
All other horses at the Halton boarding facility have been vaccinated for strangles and are being monitored by veterinarians.
In all three cases, facility owners have worked with veterinarians to institute voluntary animal movement restrictions and biosecurity protocols.
Strangles has been designated as an “immediately notifiable disease” under the Health Animal Act since February 2023, meaning all veterinary diagnostic laboratories in Ontario must report positive strangles test results to OMAFA.
Strangles is transmitted through horse-to-horse contact and can be carried on people’s skin and clothing, as well as equipment.
Identifying strangles as early as possible is key to reducing its spread. Temperatures often rise a day or two before the horse starts shedding the contagions, so isolating a horse as soon as its temperature rises can significantly slow the spread.
The best way to prevent horses from contracting strangles is limiting potential exposure to the disease, according to a consensus statement from the American College of Veterinary Internal Medicine (ACVIM).
“Quarantine and screening of all new arrivals, appropriate disinfection and cleaning of potentially contagious equipment, and education of caretakers on proper hygiene” are measures ACVIM recommends equine facilities take to decrease the risk of contracting strangles.
