Prevalence of and risk factors for equine obesity in Great Britain based on owner-reported body condition scores

Reasons for performing the study: Few data are available on the prevalence of obesity in the general equine population of Great Britain (GB), and its associated risk factors. Objectives: To estimate the prevalence of owner-reported obesity in veterinary-registered horses and ponies in GB, and identify factors associated with obesity. Study design: A cross-sectional survey of horse/pony owners in GB was undertaken using a postal questionnaire. Methods: Thirty veterinary practices randomly selected horse/pony owners to complete a self-administered postal questionnaire. Owners estimated body condition score using a modified Carroll and Huntington method (1-6 scale), and animals were classified as obese if they were scored as either 5 (fat) or 6 (very fat). Factors associated with obesity were assessed using logistic regression analysis. Results: Prevalence of obesity was 31.2% (n = 247/792; 95% confidence interval [CI] 27.9-34.2%). Factors associated with increased odds of obesity were breed (P<0.001), ease of maintaining weight (P<0.001) and primary use (P = 0.002). Compared to Thoroughbreds, draught-type (odds ratio [OR] 7.3; 95% CI 3.1-17.1), cob-type (OR 5.6; 95% CI 2.5-12.5), native (OR 3.2; 95% CI 1.8-5.78) and Welsh breeds (OR 3.5; 95% CI 1.9-6.2) were more likely to be obese. Animals described as 'good doers' were more likely to be obese than those described as readily maintaining normal weight (OR 3.7; 95% CI 2.6-5.3). Compared to competition animals, animals used for pleasure riding (OR 2.5; 95% CI 1.4-4.4) and nonridden animals (OR 2.9; 95% CI 1.5-5.5) were more likely to be obese. Conclusions: Identification of at-risk breeds and other horse-and management-level risk factors for obesity will enable optimal targeting of owner education regarding management strategies to reduce the frequency of equine obesity.