Some subclinically affected horses can return home or remain there while being treated if owners follow a few important biosecurity guidelines, such as isolating the affected animal, particularly from susceptible groups such as young and pregnant horses. | Photo: Alexandra Beckstett/The Horse

The bacterium Salmonella enterica can spread quickly between horses on a farm or in a hospital setting, causing significant financial and even equine losses. So during the 2018 British Equine Veterinary Association Congress, held Sept. 12-15 in Birmingham, U.K., Nathan Slovis, DVM, Dipl. ACVIM, CHT, of Hagyard Equine Medical Institute, in Lexington, Kentucky, described how to manage these cases for the best outcomes.

The hallmark sign of this infectious and zoonotic (can transfer between humans and animals) disease is profuse diarrhea. It typically spreads via the fecal-oral route but can also be shed by subclinical horses (those carrying the bacteria without showing signs) after stressful situations such as trailering or showing. Horses at most risk include neonates, animals on antibiotics, and stressed animals, Slovis said.

Along with the obvious concern of sick and contagious horses, the impact of a Salmonella outbreak on a veterinary clinic is substantial. Slovis said an outbreak cost one hospital close to $300,000 in expenses related to disinfecting the facility as well as lost income as a result of closures and associated legal fees. This is why it’s particularly important to identify and manage subclinical horses appropriately