Heel erosion and other interdigital disorders in dairy cows: associations with season, cow characteristics, disease, and production.

Epidemiologic associations between variables obtainable from dairy cow records and the occurrence of heel erosion, interdigital dermatitis, and interdigital hyperplasia at claw trimmings were estimated with multivariable logistic regression analysis on data from 1170 and 542 cows in lactation 1 and lactations 2 to 9, respectively. In the 17 herds, heel erosion, interdigital dermatitis, and hyperplasia occurred among 43.8, 4.5, and .9% of cows in lactation 1 and among 69.1, 7.6 and 5.9% of cows in lactations 2 to 9, respectively. Severity of heel erosion increased with parity, and risk increased with stage of lactation. Strong seasonal effects were present. Various combinations of veterinary treatments were associated with heel erosion and hyperplasia depending on parity, stage of lactation, and the presence of other claw disorders. In contrast, veterinary treatment had a protective effect for interdigital dermatitis in lactations 2 to 9. Severe degrees of sole ulcer increased the risk of heel erosion and interdigital dermatitis. The digital disorders were strongly associated in lactation 1 but not in later lactations. Heel erosion and hyperplasia were highly repeatable from one lactation to another.