horse receiving IV fluids in vet clinic

Learn to navigate the murky waters of diagnostic testing for this zoonotic disease

Watery, projectile fluid coming from the back end of an adult horse is hard to miss, but the underlying cause often isn’t easy to see. In approximately 50% of all cases of adult diarrhea (caused by enteritis/colitis—inflammation of the small intestine and colon, respectively), veterinarians never identify a definitive cause, even if an infectious disease is likely to blame, and even with thorough diagnostic testing.

“When diagnosable, Salmonella is a frequently fingered cause of diarrhea in adult horses, and Salmonella Typhimurium is a common serotype isolated,” says Luis (Memo) Arroyo, Lic. Med. Vet., DVSc, PhD, Dipl. ACVIM, an associate professor at the University of Guelph’s Ontario Veterinary College, in Canada. “Arriving at a final diagnosis remains a cornerstone at referral hospitals and does help with infectious control and biosecurity protocols for field practitioners, owners, and farm personnel/managers.”

Due to Salmonella’s zoonotic (transmissible between ­animals and humans) potential, testing is especially important in outbreak situations or cases where the bacterial disease is

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