Kentucky equine groups update Salmonella vaccine for emerging strains

Hagyard Equine Medical Institute, the University of Kentucky’s Gluck Equine Research Center, and the Kentucky Thoroughbred Association are updating an equine Salmonella vaccine to address emerging strains, including Salmonella Saintpaul, identified through genomic surveillance. In a June 5 press-release-based report, the partners said the newest iteration adds two new subspecies aimed at improving protection against Salmonella infections in horses. (equimanagement.com)

The project revives a long-running Kentucky collaboration. According to the announcement, Gluck researcher John Timoney and Hagyard veterinarians developed Salmonella and Clostridium vaccines roughly 15 years ago in response to disease pressure in the Central Kentucky Thoroughbred population. The current update comes after clinicians reported seeing more horses with Salmonella in recent years, prompting work to improve the existing product rather than start from scratch. (equimanagement.com)

The scientific backdrop is stronger than a routine product refresh. A 2026 Veterinary Microbiology paper from University of Kentucky-affiliated researchers reported that, among 245 equine Salmonella enterica subsp. enterica isolates collected between 2018 and 2025, S. Saintpaul emerged as an important concern. It was detected in 21 equine cases in 2025, all from Central Kentucky, and was linked to enterocolitis, bronchopneumonia, omphalitis, and septicemia, mainly in young foals. Whole-genome sequencing of 16 isolates showed low genetic diversity, supporting the idea that these cases were part of a closely related strain cluster. (scholars.uky.edu)

That paper also helps explain why vaccine updating may matter now. The S. Saintpaul isolates showed multidrug resistance, particularly to aminoglycosides, beta-lactams, tetracyclines, and sulfonamides, and carried resistance genes including blaCTX-M-32, blaCMY-2, sul1, dfrA34, and rmtE1. In the press release, Yosra Helmy, DVM, PhD, associate professor at Gluck, said whole-genome sequencing identified the circulating strain and supported a targeted vaccine update. The release also said Kentucky isolates closely resembled strains tied to outbreaks in Texas and Georgia in 2023, suggesting the issue may not be purely local. (scholars.uky.edu)

The announcement offers only limited product specifics, but it does identify the main players behind development and support. Hagyard said Nathan Slovis, Luke Fallon, the Hagyard Laboratory, and other practice veterinarians led the vaccine enhancement and efficacy assessment, while the Kentucky Thoroughbred Association provided financial support and Gluck contributed pro bono research work. KTA has a track record of backing equine health research at UK, including prior funding support for Gluck facilities and studies. (equimanagement.com)

Expert reaction in the available coverage is mostly from the collaborators themselves, but the framing is notable. Slovis said veterinarians had observed an increase in horses with Salmonella, while Helmy emphasized rapid translation of genomic data into field protection. Separately, Slovis was listed this spring as a speaker on biosecurity lessons from Salmonella and strangles for the Kentucky Thoroughbred Farm Managers’ Club, which reinforces that this work is landing in an environment where farm-level infectious disease prevention remains a live operational issue. (equimanagement.com)

Why it matters: For veterinary professionals, especially equine ambulatory, internal medicine, neonatal, and hospital teams, this story sits at the intersection of diagnostics, antimicrobial stewardship, and outbreak prevention. A vaccine update tied to local genomic surveillance suggests a more adaptive approach to endemic and emerging equine bacterial threats. If the updated vaccine performs as intended, it could become another tool for reducing case burden, antibiotic use, environmental contamination, and occupational exposure risk for veterinary staff and farm workers. That said, the public information so far does not include challenge data, duration of immunity, field effectiveness, manufacturing pathway, or regulatory details, so clinicians should view this as a promising development rather than a fully characterized new standard. (scholars.uky.edu)

What to watch: The next key signals will be whether the partners publish efficacy results, clarify how the added subspecies map to circulating field strains, and outline availability or use recommendations for breeding farms, referral hospitals, and other high-risk equine settings. Because the announcement describes a targeted update driven by 2025 surveillance findings, follow-up publications and any broader regional surveillance data will matter as much as the vaccine news itself. (scholars.uky.edu)