INTRINSIC, MANAGEMENT, AND NUTRITIONAL FACTORS ASSOCIATED WITH EQUINEMOTOR-NEURON DISEASE

Objective-To identify intrinsic, management, nutritional, and environm ental risk factors associated with equine motor neuron disease (EMND) and to deter mine whether epidemiologic evidence supports oxidative st ress as a risk factor for developing EMND. Design-Case-control study. Animals-87 horses with EMND and 259 control horses. Procedure-informat ion concerning each horse's history of exposure to multiple environmen tal factors prior to developing EMND was obtained by means of a questi onnaire or personal interview. Exposure histories of horses with EMND and control horses were compared, and the association of each risk fac tor with EMND was evaluated, using logistic regression analysis. Resul ts-Factors significantly associated with risk of developing EMND inclu ded age, breed of horse, duration of residence at the farm, not vaccin ating against rabies, and certain feeding practices. Horses that were exercised on green pasture or in grass paddocks were less likely to de velop EMND, compared with horses that were exercised in dirt paddocks. Feeding complete pelleted feed as the only source of concentrate or c ombined with sweet feed was associated with a significant increase in the risk of EMND. Supplementary feeding of vitamin and mineral mixture s not formulated to provide vitamin E or selenium was associated with increased risk of EMND. Horses with a history of cribbing or coprophag ia were also at higher risk of developing EMND. Clinical implications- Several husbandry practices and intrinsic characteristics of horses ap pear to modify the risk of EMND. The relationship of specific nutritio nal factors to EMND supports the hypothesis that a deficiency of vitam in E contributes to the disease.