Obesity is increasingly prevalent in domestic horses and ponies, with surveys suggesting 30-50% of UK equines are overweight or obese. The welfare consequences—particularly laminitis risk and metabolic disease—are significant and largely preventable through appropriate management.
Horse and pony obesity reflects the mismatch between domesticated feeding practices and evolved metabolic physiology. Modern management often provides ad libitum high-quality pasture or hay, combined with reduced exercise requirements compared to working horses. Native pony breeds are particularly susceptible—evolved for sparse, seasonal nutrition, their efficient metabolisms accumulate fat rapidly when offered unrestricted access to lush grass or high-energy diets.
The primary welfare concern of equine obesity is laminitis risk through insulin dysregulation. Obese horses and ponies have elevated resting insulin and exaggerated insulin responses to non-structural carbohydrate intake, driving inflammation in the laminar tissue. Equine metabolic syndrome (EMS)—characterised by obesity, laminitis, and insulin dysregulation—is the dominant metabolic disease of modern horses. Additional consequences include increased anaesthetic risk, reduced performance, and joint loading exacerbating musculoskeletal problems.
The Henneke Body Condition Score (1-9 scale) provides standardised adiposity assessment. Additional "cresty neck score" (0-5) specifically assesses nuchal ligament fat deposition—a particular EMS risk indicator. Girth tapes provide weight estimation. Regular, consistent assessment by the same person at the same time enables meaningful trend monitoring. Photograph documentation supports objective comparison over time.
Safe equine weight loss is gradual (0.5-1% body weight per week maximum) to prevent hyperlipaemia, particularly in ponies. Strategies include: soaked hay provision (soaking reduces NSC content by up to 30%); measured hay allowance (1.5% dry matter body weight for weight loss vs. 2-2.5% for maintenance); restricted grazing using strip grazing, muzzles, or dry lot management; removal of hard feed supplements for overweight animals; and increased controlled exercise if metabolically stable.
Appropriate exercise accelerates weight loss, improves insulin sensitivity, and maintains muscle mass during dietary restriction. In horses with active laminitis, exercise is contraindicated. Once metabolically stable and sound, gradual exercise increase—walking, then light trotting—improves insulin sensitivity and supports weight management. Environmental enrichment (larger paddocks, track systems) increases voluntary activity in less intensively managed horses.