On March 7, a three-year-old filly from Clinton County, Michigan, tested positive for strangles. On March 6, the filly developed clinical signs such as nasal discharge, lethargy, and inappetence. She is under quarantine, and eleven horses have been exposed.
EDCC Health Watch is an Equine Network marketing program that uses data from the Equine Disease Communication Center (EDCC) to generate and distribute verified equine disease reports. The EDCC is an independent nonprofit organization that relies on industry donations to provide open access to infectious disease information.
About Strangles
Strangles in horses is an infection caused by Streptococcus equi subspecies equi, which spreads through direct contact with other horses or contaminated surfaces. Horses that do not show clinical signs can harbor and spread the bacteria, and recovered horses are contagious for at least six weeks, potentially leading to long-term outbreaks.
Infected horses can exhibit a variety of clinical signs:
- Fever
- Swollen and/or abscessed lymph nodes
- Nasal discharge
- Coughing or wheezing
- Muscle swelling
- Difficulty swallowing
Veterinarians diagnose horses using polymerase chain reaction (PCR) testing on a nasal swab, wash, or abscess sample, and treat the majority of cases based on clinical signs, with antibiotics used for severe cases. Antibiotic overuse may prevent an infected horse from developing immunity. Most horses recover fully within three to four weeks.
A vaccine is available, but it does not always work. Biosecurity measures such as quarantining new horses at a facility, maintaining high hygiene standards, and disinfecting surfaces can help reduce the risk of an outbreak or contain it if it occurs.
