Washington State Veterinarian
This week, a Snohomish County horse that recently attended a show in Whatcom County was diagnosed with strangles, Streptococcus equi, an endemic bacterial infection that is rarely fatal, but as the name suggests, can affect a horse’s respiratory system.
There is no evidence the horse was contagious at the time or that it contracted the disease at the show.
Since January, there have been reports of six other confirmed, laboratory-diagnosed cases of strangles in Okanagan, Clallam, Kitsap, and Pierce counties.
Private veterinarians usually manage the strangles cases reported to the Washington State Veterinarian’s Office, including imposing self-quarantine, implementing biosecurity measures, and executing testing protocols. WSDA field veterinarians contact those veterinarians to monitor these cases and provide support, including issuing official quarantine orders in some cases.
When a quarantine is in effect, no horses are allowed to move on or off the premises, attend horse shows, or travel. It is actually against the law to expose other animals to contagious, infectious, or communicable diseases.
How to protect your horse against strangles
Any time you attend a show, WSDA recommends monitoring horse’s body temperatures twice a day and isolating horses for up to three weeks to monitor for disease. Oftentimes, fever will precede illness and early detection can help prevent disease transmission. The incubation period (time of exposure to time of clinical signs) can range from 3-14 days. While strangles is a concern to many horse owners, there have also been several cases of Equine Herpes Myeloencephalopathy reported in California, a potentially fatal viral disease showcasing why biosecurity practices are critical for horses that attend exhibitions or other events.
Strangles is rarely fatal and the prognosis for recovery is usually very good with proper care. Symptoms include:
- Fever
- Abscesses in the mandibular lymph nodes
- Nasal discharge that can include thick white and yellow mucus
- Inflammation of the throat
- Difficulty swallowing
- Wheezing
- Coughing
- In rare cases, bleeding from the capillaries
Good biosecurity practices are the best defense against the disease. The Equine Disease Communication Center’s “What is biosecurity?” offers excellent recommendations.
The EDCC also recommends the following:
- When possible, isolate new horses for up to three weeks when they are being introduced to a new facility.
- If you have handled an infected animal during an outbreak, avoid coming in contact with susceptible animals.
- Wear protective clothing, avoid using the same equipment on multiple animals, and disinfect both your hands and equipment when moving between animals.
This “Strangles Fact Sheet” from the EDCC has more information on this disease, tips and suggestions.
Remember to notify WSDA if you become aware of a reportable disease by visiting our “Reportable Diseases” webpage.