Individual cow risk factors for clinical lameness in lactating dairy cows

A case-control study investigating relationships between clinical lameness and individual-cow (within herd) risk factors was performed in 17 Minnesota and Wisconsin dairy herds. Cases were defined as lactating cows found lame by either of two observers during farm visits in the summer of 1989 and spring of 1990 using a uniform scoring system. A single control cow (matched by herd, season, parity, and stage of lactation) was selected for each case at each visit. Assessments of body weight, body condition, dorsal claw angles, and limb lesions were made for each case and control animal. Conditional logistic regression analysis revealed positive associations between prevalent clinical lameness and heavier body weight, lower body condition score, and shallower slope of rear lateral claw angle. Lesions associated with clinical lameness included non-tarsal rear limb superficial swellings, abnormal hoof overgrowth (including corkscrew claw), and limb lacerations. Superficial tarsal swellings, intra-synovial tarsal swellings, and carpal swellings were not associated with clinical lameness.