A horse can have EMS without being overweight

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Horses don’t have to be overweight to have equine metabolic syndrome, or EMS. In a new explainer for The Horse, equine nutritionist Shannon Pratt-Phillips says some horses with a normal body condition score can still have the insulin dysregulation that defines EMS and raises laminitis risk. That point aligns with current veterinary guidance: Merck Veterinary Manual describes EMS as a syndrome centered on insulin dysregulation, notes that affected animals are often obese with regional fat deposits, but also recognizes a lean EMS phenotype. Recent coverage from The Horse likewise highlighted that “lean-type” EMS exists and that even athletic horses can be affected. (merckvetmanual.com)

Why it matters: For veterinary professionals, the practical message is not to rule out EMS based on appearance alone. Consensus and reference sources emphasize that diagnosis should focus on documenting insulin dysregulation rather than relying only on body condition score, especially in horses with regional adiposity, breed predisposition, laminitis history, or mixed endocrine signals. Cornell’s testing guidance points clinicians toward insulin testing, oral sugar testing, and leptin as follow-up tools, while Merck notes that management decisions should be guided by insulin response and laminitis risk, not just weight. (vet.cornell.edu)

What to watch: Expect continued emphasis on phenotype-specific EMS screening and management, especially as updated Equine Endocrinology Group recommendations are incorporated more broadly into practice. (ebvminpractice.org)