Recently, a 13-year-old Lusitano gelding in Washtenaw County, Michigan, was diagnosed with strangles after developing a fever and nasal discharge on April 16. The horse is currently recovering, and two other horses have been exposed to the infection.
EDCC Health Watch is a program by Equine Network that utilizes information from the Equine Disease Communication Center (EDCC) to provide verified equine disease reports. The EDCC is a nonprofit organization supported by industry donations, offering open access to infectious disease information.
Understanding Strangles
Strangles in horses is caused by Streptococcus equi subspecies equi and is transmitted through direct contact with infected equids or contaminated surfaces. Even horses without symptoms can carry and spread the bacteria, with recovered horses remaining contagious for up to six weeks, potentially leading to long-term outbreaks.
Common clinical signs of strangles in infected horses include:
- Fever
- Swollen or abscessed lymph nodes
- Nasal discharge
- Coughing or wheezing
- Muscle swelling
- Difficulty swallowing
Veterinarians typically diagnose strangles using polymerase chain reaction (PCR) testing with samples from nasal swabs, washes, or abscesses. Treatment is often based on clinical signs, with antibiotics prescribed for severe cases. However, overuse of antibiotics can hinder the horse’s ability to develop immunity. Most horses recover fully within three to four weeks.
While a vaccine is available, its effectiveness varies. 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 when they occur. Learn more about protecting your horse from strangles and handling outbreaks on the farm.