Horses in three Florida counties have tested positive for strangles. In Manatee County, a 2-year-old Quarter Horse gelding tested positive after developing fever, lymphadenopathy, mucopurulent nasal discharge, and a draining abscess on November 24. The horse is quarantined. Four other cases are suspected, and 78 horses were exposed.

In Marion County, a weanling Gypsy colt tested positive on December 19 after developing fever, mucopurulent nasal discharge, lymphadenopathy, and a draining abscess starting on December 14. The horse is quarantined, and 24 horses are exposed.

In Gilchrist County, a yearling Standardbred gelding tested positive on December 9 after developing a fever on December 6. The horse is quarantined, and 17 other horses are exposed.

Florida has now had 47 confirmed cases of strangles in 2022.

EDCC Health Watch is an Equine Network marketing program that utilizes 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 industry donations in order to provide open access to infectious disease information.

About Strangles

Strangles in horses is an infection caused by Streptococcus equi subspecies equi and spread through direct contact with other equids or contaminated surfaces. Horses that aren’t showing clinical signs can harbor and spread the bacteria, and recovered horses remain contagious for at least six weeks, with the potential to cause outbreaks long-term.

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 with either a nasal swab, wash, or an abscess sample, and they 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 at a facility and maintaining high standards of hygiene and disinfecting surfaces can help lower the risk of outbreak or contain one when it occurs.