The British Columbia Dairy Hoof Health Group has created HARP-DD (Hoof Assessment and Recommended Practices for Digital Dermatitis Control), a risk assessment tool aimed at helping to reduce the prevalence of digital dermatitis (DD) by identifying and addressing on-farm risk factors for infection.
Few claims about the efficacy of products used to treat digital dermatitis (DD) are supported by any conclusive scientific evidence. Not all treatment trials provide conclusive evidence – many reported trials are poorly designed, leading to bias towards a particular outcome.
A recent study considered a large number of DD treatment trials, eliminating all but four that were rigorously designed to give conclusive, unbiased results.
Researchers at the University of Wisconsin have demonstrated that acute digital dermatitis (DD) in 16 – 25 month old heifers can increase heel height, claw angle and depth of the interdigital cleft. DD lesions were also associated with significant increases in heel horn erosion.
Previous studies have demonstrated that multiple bacterial species are associated with digital dermatitis (DD) lesions, with spirochetes being the most commonly identified organism. A recent study at Iowa State University demonstrated that, although spirochetes are the predominant bacteria present in the later stages of lesion development, many other bacterial species are involved in the earlier stages.
With digital dermatitis (DD) now being implicated in non-healing hoof lesions, its control is becoming more important than ever. Footbathing remains the key way of controlling DD infections on-farm, according to British veterinarian Sara Pedersen who says:
“Digital dermatitis is often described as ‘mastitis of the foot’, so foot bathing can be considered the equivalent to teat dipping in mastitis control. It can also help harden the hoof and make it less susceptible to penetrating injuries or shearing forces.”
The frequent claim that copper sulfate (CuSO4) is effective in controlling digital dermatitis (DD) is supported by little scientific evidence. Only one of seven articles evaluated in a recent study found a positive effect of CuSO4. In addition, most of these studies are relatively small, do not compare CuSO4 with no treatment (negative control), and, often, no clear positive effect of CuSO4 is demonstrated. Until better studies have been conducted, the efficacy of CuSO4 foot baths in controlling DD remains largely unproven.
Copper sulfate disposal from dairy farm footbaths can result in significant accumulation of copper in soil which may be detrimental to crop growth. Regulators in several US states have established maximum soil loading rates for copper.
The threat of tetracycline residues ending up in the bulk tank is one for dairy producers to take seriously. While the legal limit for the drug in milk is 300 ppb in the U.S. and 100 ppb in Canada, there are processors running tests that can detect as little as 10 to 30 ppb – and by some of their standards, that could mean rejecting a load of milk.
According to Dr. Nigel Cook, achieving a high level of herd performance and controlling lameness go hand-in-hand.
“You cannot manage your herd successfully unless you manage lameness,” he said. “It undermines everything you try to do. It impacts the way the cow behaves, the way she walks, the way she eats, the way she rests. It impacts reproduction and increases the risk for early removal.”
In a survey of 22 intensively managed, high-producing commercial dairies in Wisconsin, Cook compared lameness prevalence to that of cows kept primarily on pasture.
Three new factsheets address the causes, prevention and treatment of each of the 3 most common dairy cattle claw lesions: digital dermatitis, sole ulcer and white line lesion. The factsheets are written in plain language, designed to help producers deal with these lesions.