At the 2018 Western Canadian Dairy Seminar (WCDS), Dr. Gerard Cramer explained how cows can become chronically lame if damage to their hooves is not treated early and if there is no follow-up evaluation.
Sole hemorrhage, sole ulcer and white line lesions, collectively referred to as claw horn disruption lesions (CHDL), are the most common non-infectious claw lesions of dairy cattle worldwide. The photographs in figure 1 illustrate these lesions.
An important risk factor for sole hemorrhages and ulcers is thinning of the digital cushion (figure 2) which acts as a shock absorber between the pedal bone and the walking surface. Thin digital cushions are associated with low body condition scores (see article here). White line lesions are associated with excessively rough or slippery flooring surfaces especially when cows are required to make sharp turns as the travel on those surfaces (see article here). Excessive standing time is a risk factor for all of these CHDL.
Several research studies have reported that cows with severe CHDL are at higher risk of recurring lameness and failure to treat these lesions early in their development can lead to anatomical damage of the claw. Dr. Cramer described recent findings from studies in the UK (summarized here) demonstrating that cows with history of lameness develop bony structures in the pedal bone that are irreparable (figure 3).
From other studies, we also know that hormonal changes around calving cause relaxation of the suspensory tendons which holds the bones of the digit in place (figure 2) resulting in movement and sinking of the pedal bone. Dr. Cramer explained how this puts pressure on the corium, causing inflammation which, in turn, leads to the changes in the bone described above. These changes create a perpetual cycle, with inflammation playing a key role in the recurrence of lesions
Appropriate treatment of CHDL involves the application of a block on the opposite claw (assuming it is healthy) and the administration of a non-steroidal anti-inflammatory drug (NSAIDs, e.g., ketoprofen, meloxicam) to control inflammation (see article here).
Dr. Cramer’s bottom line is this: Controlling lameness due to CHDL requires an integrated approach that focuses on prevention and early, effective treatment of chronically lame cows. Prevention starts with ensuring appropriate lying time, minimizing inflammatory and metabolic incidents around the transition period, and ensuring all cows receive an appropriate hoof trimming around dry-off. If a cow does become lame, applying appropriate treatment with the use of blocks and NSAIDs, along with a follow-up evaluation is essential.
This article was originally published in the Spring 2018 issue of BC Holstein News. Dr. Cramer’s 2018 WCDS paper is here.