SYMPOSIUM: LAMINITIS INVESTIGATIONS Investigation Strategies for Laminitis Problem Herds

Lameness in dairy cows includes many disease conditions, and a systematic approach is required to diagnose the predominant causes and identify the important risk factors. Lameness prevalence can be quantified using locomotion scoring systems. Entire herds can be scored quite easily as they walk access lanes. If lameness prevalence exceeds 15% of the herd, it is important to differentiate the cause. Improved hoof health recording systems have become commonplace amongst many professional hoof trimmers, which has made it easier to monitor the prevalence of infectious and non-infectious causes of lameness. If laminitis and its associated claw horn lesions are identified as a major problem, environmental and ruminal acidosis risk factors should be assessed. Environmental risk factors for laminitis include aberrant and excess standing behavior, exposure to concrete and hard floor surfaces and abrupt introduction to confinement systems from pastures or bedded packs. Total daily time spent by cows in holding areas and parlors can be assessed, emphasizing the longest times for the last individual cows to come through the parlor. Stall usage indices are being developed to identify poorly designed or maintained freestalls. The diagnosis of ruminal acidosis is made with a combination of clinical signs, ration evaluation, ruminal fluid analysis, feces examination, or milk fat indicators. Rumenocentesis is a direct measure of rumen pH that can provide diagnostic information, provided that adequate samples are collected. This paper presents a clinical approach to investigations of lameness problem herds and discusses strengths and weaknesses of various tests to identify risk factors for laminitis.