
The State Department of Agriculture reported that a horse at a veterinary hospital in Marion County, Oregon, was euthanized due to contracting strangles. No quarantine measures have been imposed in relation to this case.
EDCC Health Watch is a program by Equine Network that utilizes data from the Equine Disease Communication Center (EDCC) to generate and distribute authenticated reports on equine diseases. The EDCC is an independent nonprofit organization funded by industry contributions to provide accessible information on infectious diseases.
About Strangles
Strangles in horses is a bacterial infection caused by Streptococcus equi subspecies equi, transmitted through direct contact with infected equids or contaminated surfaces. Even asymptomatic horses can carry and spread the bacteria, with recovered horses remaining contagious for up to six weeks, posing a long-term risk of outbreaks.
Common clinical signs of strangles include:
- Fever
- Swollen or abscessed lymph nodes
- Nasal discharge
- Coughing or wheezing
- Muscle swelling
- Difficulty swallowing
Veterinarians typically diagnose strangles in horses using polymerase chain reaction (PCR) testing on nasal swabs, washes, or abscess samples. Treatment is often based on clinical symptoms, with antibiotics prescribed for severe cases. Overuse of antibiotics can hinder the development of immunity in infected horses, but most horses recover fully within three to four weeks.
While a vaccine is available, its effectiveness can vary. Implementing biosecurity measures such as quarantining new horses and maintaining strict hygiene practices, including surface disinfection, can help reduce the risk of outbreaks or manage them effectively when they occur. Learn more about protecting your horse from strangles here and how to handle strangles outbreaks on the farm.

