Investigating herds with lameness problems.

Many dairy herds have unusual or exceptionally serious lameness problems. Based on published observations of risk factors for specific disease problems, along with the author's experience, this article describes a systematic way to approach and evaluate lameness problems. It is important to define the etiologic diagnosis because preventive or corrective measures depend on the cause of the herd problem. Compound etiologies and complex risk factor interactions are the norm in this sometimes frustrating endeavor.