Why chronic diarrhea in horses demands a careful differential

The Horse has published a new clinical explainer, “Running Loose: Tackling Chronic Diarrhea in Horses,” focused on a problem equine veterinarians see regularly but define carefully: not every “loose” case is true chronic diarrhea. The key distinction is between chronic diarrhea, which can signal serious intestinal disease and systemic compromise, and free fecal water syndrome, in which horses pass normal fecal balls with separate liquid and are often otherwise clinically well. That distinction matters because adult-horse diarrhea can become serious quickly, while free fecal water syndrome is usually more of a management and skin-care issue unless it reflects a broader gastrointestinal problem. (merckvetmanual.com)

Why it matters: For veterinary professionals, the practical takeaway is diagnostic discipline. Equine experts have emphasized a methodical workup that starts with history, physical exam, bloodwork, protein and electrolyte assessment, and fecal testing, while keeping infectious causes, parasites, inflammatory bowel disease, sand enteropathy, diet-related factors, and other systemic disease on the differential list. AAEP’s current field guidance also underscores that some diarrheal presentations carry biosecurity and zoonotic implications, including pathogens such as Salmonella, Clostridioides difficile, rotavirus, and equine coronavirus. (thehorse.com)

What to watch: Expect continued attention on how clinicians separate benign free fecal water cases from horses that need deeper investigation for inflammatory, infectious, parasitic, or protein-losing intestinal disease. (thehorse.com)