A multicenter, matched case-control study of risk factors for equine laminitis

Risk factors for equine laminitis were examined in a prospective case-contr ol study of the 258 cases seen at six collaborating veterinary teaching hos pitals over a 32-month period. Case-control pairs were matched on instituti on, clinician, and season of diagnosis. The 90% of case-control pairs (78 a cute, 155 chronic) that had complete data for age, gender, and breed were u sed in separate conditional logistic-regression models for acute and chroni c laminitis. There was an increase in risk for horses with acute laminitis from 5 to 7 years of age (OR 4.7, 95% CI 1.3-16) and from 13 to 31 years of age (OR 3.9, 95% CI 1.3-12) (both compared to <5 years); risk was increase d for chronic laminitis from 10 to 14 years (OR 3, 95% CI 1.4-6.8) and from 15 to 38 years (OR 2.9, 95% CI 1.4-6.1) (both compared to <6 years). Mares - but not stallions - were more likely than geldings to develop acute lami nitis (OR 2.6, 95% CI 1.1-6.2) and chronic laminitis (OR 2.0, 95% CI 1.1-3. 6). In the small acute-laminitis data set, the breed variable was collapsed into three categories: Thoroughbred (THB, reference), the Quarter Horse (Q H), and other (non-QH-THB). The non-QH-THB group was at increased risk of a cute laminitis (OR 3.8, 95% CI 1.2-11.8). For the seven breed-group categor ies used in the chronic-laminitis model, however, all non-THE breed groups appeared significantly at risk as compared to the THE, with odds ratios ran ging from 3.3 (95% CI 1.3-8.30) for the QH to 9.1 (95% CI 2.1-39.3) for pon ies. (C) 2001 Elsevier Science B.V. All rights reserved.