A single horse at a boarding facility in Ottawa County, Michigan, has been confirmed to have strangles. There is currently no information on whether other horses may have been exposed to the infection.
EDCC Health Watch is a marketing program by Equine Network that utilizes information from the Equine Disease Communication Center (EDCC) to generate and distribute verified reports on equine diseases. The EDCC is a nonprofit organization that operates independently and is funded by industry donations to provide accessible information on infectious diseases.
About Strangles
Strangles is an infection in horses caused by Streptococcus equi subspecies equi and is transmitted through direct contact with other equids or contaminated surfaces. Even asymptomatic horses can carry and spread the bacteria, and recovered horses can remain contagious for up to six weeks, potentially leading to long-term outbreaks.
Symptoms of an infected horse may include:
- Fever
- Swollen and/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 with samples from nasal swabs, washes, or abscesses. Treatment is usually based on clinical signs, with antibiotics being administered in severe cases. However, excessive antibiotic use can hinder the development of immunity in the infected horse. Most horses recover fully within three to four weeks.
Although a vaccine is available, its effectiveness is not guaranteed. Implementing biosecurity measures such as quarantining new horses and maintaining high levels of hygiene and surface disinfection can help reduce the risk of outbreaks or contain them if they occur.

