Two Wisconsin horses tested positive for strangulation. One horse is a 22-year-old percheron living at a boarding facility in Racine County. He was taken for strangulation on October 29 after showing respiratory signs and abscesses. The horse was placed in voluntary quarantine. Strangles was confirmed on November 2 and the horse is now recovering. Other horses in the barn were also showing clinical signs and were seen by other veterinarians.
The second horse is a five-year-old Quarter Horse that is in a training facility in Outagamie County. The horse had respiratory signs and abscesses. He was sampled for strangulation on October 27 and was confirmed positive by PCR. A follow-up nasal swab on November 14 was negative for PCR. No other horses showed clinical signs and the gelding is now recovering.
EDCC Health Watch is an equine network marketing program that uses information from the Equine Disease Communication Center (EDCC) to create and disseminate verified equine disease reports. The EDCC is an independent nonprofit organization that is supported by donations from industry to provide open access to information about infectious diseases.
Strangulation in horses is an infection caused by Streptococcus equi subspecies flo and spread through direct contact with other equids or contaminated surfaces. Horses without clinical signs can harbor and spread the bacteria, and recovered horses remain contagious for at least six weeks, with the potential to cause long-term outbreaks.
Infected horses can show a variety of clinical signs:
- Swollen and/or abscessed lymph nodes
- Runny nose
- Coughing or wheezing
- Muscle swelling
- Difficulty swallowing
Veterinarians diagnose horses using the PCR test, either with a nasal swab, wash, or abscess sample, and treat most cases based on clinical signs, implementing antibiotics for severe cases. Overuse of antibiotics can prevent an infected horse from developing immunity. Most horses make a full recovery in three to four weeks.
A vaccine is available, but not always effective. Biosecurity measures of quarantining new horses in a facility and maintaining high standards of hygiene and surface disinfection can help decrease the risk of an outbreak or limit one when it does occur.