“What do animal diseases have to do with people?” posed Scott Weese, DVM, DVSc, Dipl. ACVIM, an associate professor at the University of Guelph’s Ontario Veterinary College. “We are just one big global population with subsets,” he answered. Weese discussed methicillin-resistant Staphylococcus aureus (MRSA), a multi-drug-resistant bacterium that affects humans and horses. He said that one of the leading causes of hospital-acquired infections in humans is “superbugs like this. MRSA infections have recently begun spilling over into the community, spreading outside of hospitals as well.

Weese spoke during the “Cutting Edge of Animal Health” series of internal medicine topics presented to the press on June 2 at the annual meeting of the American College of Veterinary Internal Medicine (ACVIM) in Baltimore, Md. Weese has focused his research on MRSA infections for several years, learning how this and similar “superbugs” work and the best ways to eradicate them.

Antibiotic-resistant infections in horses are not simply a direct spillover from humans. Some of these “bugs” have adapted over time to more effectively infect the horse’s body. A veterinary hospital employee can bring an MRSA infection to work (such as in his nasal passages), then pass it on unknowingly to an immune-compromised equine patient, who can then pass it on to other horses or humans.

The prevalence of MRSA is a concern because of the problems it’s already causing at hospitals and because of the problems that it’s likely to cause if veterinarians aren’t aware of it. “There’s no organization tracking it (in horses) in the United States, no mandate for physicians to follow up, and not all diagnostic labs are looking for it,” he said