(E61) Epidemiological Evaluation of Equine Metabolic Syndrome in Arabian Horses and Their Subgroups

Abstract:

Objective: Estimate prevalence and risk factors influencing equine metabolic syndrome (EMS) in Arabians and their subgroups. Animals: 768 Arabians (205 geldings, 85 stallions, 476 mares) from 53 farms.

Methods: Phenotypic data included basal insulin, triglycerides, leptin, insulin post oral sugar test (INS-OST), body condition score (BCS), and cresty neck score (CNS). Subgroups were defined as English (n=145), Western (n=87), leisure (n=79), lesson (n=37), halter (n=68), broodmare (n=266), breeding stallion (n=25), or retired (n=39). Prevalence was calculated across and within subgroups for binary outcome variables. Mixed model analyses were performed with biochemical measurements as quantitative outcome variables, farm as a random effect and sex, age, CNS, BCS, month, and subgroup as predictors. Pairwise comparisons identified significant differences between categorical predictors at Tukey-corrected p-values < 0.05.

Results: Across our cohort, 28% were obese, 57% had a CNS of 3, 16% had fasting hyperinsulinemia, 18% had post-OST hyperinsulinemia, and 19% had hypertriglyceridemia. Obesity and post-OST hyperinsulinemia were most common in broodmares (28%, 21%), retired (36%, 51%), and Western horses (39%, 18%). Breeding stallions had the highest prevalence of a CNS 3 (67%) but hypertriglyceridemia, hyperinsulinemia, and post-OST hyperinsulinemia were absent. Retired horses had insulin concentrations 1.7-2.3 times higher than breeding stallions (p=< 0.001), broodmares (p=0.006) or English horses (p=< 0.001). Across sex, stallions had 1.3-1.5 times lower INS-OST (p=< 0.001) and 1.4 times lower leptin concentrations (p=< 0.001) compared to geldings and mares. Conclusion and Clinical Importance: These results confirm that Arabians are a high-risk breed for EMS with differences in prevalence and risk across subgroups and sex.