PREVALENCE OF LESIONS ASSOCIATED WITH SUBCLINICAL LAMINITIS IN FIRST-LACTATION COWS FROM HERDS WITH HIGH MILK-PRODUCTION

Objective-To determine prevalence of lesions associated with subclinic al laminitis in first-lactation Holstein cows during early lactation a nd pregnant Holstein heifers during late gestation in herds with high milk production. Design-Cross-sectional study. Animals-203 cattle in 1 3 herds. Procedure-Cattle were placed in lateral recumbency to allow v isual examination and photography of their hooves. Claws on a forelimb and hind limb were examined on all cattle. Observable categories of l esions considered to be associated with subclinical laminitis in our s tudy included yellow waxy discoloration of the sole, hemorrhage of the sole, separation of the white liner and erosion of the heel. Results- Lesions in at least 1 of the categories were found in ail herds. Lesio ns in all categories were found in 11 of 13 herds, Among claws, hemorr hage of the sole was observed most frequently in the lateral claw of t he hoof of the hind limb. When days in milk was treated as a covariate , significant (P < 0.01) differences were detected in the prevalence o f lesions between herds. Clinical Implications-Because the prevalence of lesions differed significantly among herds, it is logical to believ e that causative factors and corrective measures also may have differe d among herds.