Prevalence of Overconditioning in Mature Horses in Southwest Virginia during the Summer

Abstract

The prevalence of obesity in horses in the eastern United States is not well documented. To determine body condition and risk factors for obesity in horses in Southwest Virginia during summer. A sample of 300 mature (4-20 years old), light breed horses (140 mares, 151 geldings, and 9 stallions) from the VMRCVM Equine Field Service practice equine database. The horses were from 114 farms and 138 owners. Horses were evaluated over a 60-day period in this cross-sectional, prospective study. A questionnaire was completed for each horse. Body condition score (BCS) was assigned using a scale of 1 (emaciated) to 9 (obese) by 2 independent scorers. Morphometric measurements included average neck circumference (ANC), girth, body length, and height at the withers. Horses were categorized based on BCS as underconditioned (BCS < 4), optimal condition (BCS 4-6), overconditioned (BCS 7), and obese condition (BCS 8-9). Five horses (1.7%) were underconditioned, 142 horses (47.3%) were optimally conditioned, 97 horses (32.3%) were overconditioned, and 56 (18.7%) were obese. Estimated body weight (EBW) (r = 0.14, P = .015), body mass index (BMI) (r = 0.46, P < .001), and neck circumference to height ratio (NCHR) (r = 0.50, P = .001) increased with increasing BCS. The prevalence of overconditioned and obese horses in this population was higher than reported in previous studies and indicates that obesity might be an emerging problem in horses.