Wisconsin strangles case highlights risk in vaccinated horses
A 15-year-old Paint mare in Waupaca County, Wisconsin, tested positive for strangles after developing clinical signs on October 31, 2025, with confirmation on November 6, according to an Equine Disease Communication Center alert sourced to the Wisconsin Department of Agriculture, Trade and Consumer Protection. The case was published by Equus Magazine on February 6, 2026. The mare has recovered, but three additional horses at the private facility were considered likely infected and five horses were exposed overall. Notably, the mare had been vaccinated for strangles in September 2025, and follow-up testing indicated infection with a wild strain rather than a vaccine strain. Equus’ strangles background also notes that PCR testing can be performed on a nasal swab, wash, or abscess sample; most horses recover in three to four weeks; and while a vaccine is available, it is not always effective. (equusmagazine.com)
Why it matters: For equine veterinarians and practice teams, this case is a reminder that strangles can still occur in vaccinated horses, and that mild or atypical signs in exposed horses can complicate detection. EDCC’s case details note the additional horses showed signs such as cough and limb edema rather than classic fever, nasal discharge, and draining lymph nodes. That matters for triage, testing, and client communication, especially when horses are coming from rescue settings or entering new facilities. Equus also emphasizes that quarantine of new arrivals, hygiene, and surface disinfection remain key outbreak-control tools. Merck Veterinary Manual and AAEP guidance further note that recovered horses can remain carriers, with guttural pouch testing playing an important role in identifying animals that may continue to shed Streptococcus equi. (equinediseasecc.org)
What to watch: Watch for any additional Wisconsin alerts tied to the facility, plus whether exposed horses undergo follow-up testing to rule out persistent carrier status before movement resumes. Similar recent EDCC-linked reporting from neighboring states, including a Michigan case involving a recovering 2-year-old gelding with one suspected additional case and two exposed horses, underscores that sporadic strangles activity continues to surface regionally. (equinediseasecc.org)