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.
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.
Hoof blocks, fixed under one claw to allow the other claw to recover from corrective trimming, are used to reduce pain during the healing process. A German trial compared the used of uniform thickness wood and flexible synthetic hoof blocks with wedge-shaped blocks of the same materials.
There are 2 main causes of thin soles in dairy cattle:
1. an abrasive floor, particularly a new one in a barn cows have recently moved into;
2. excessive hoof trimming.
Without immediate intervention, some cows will completely lose the sole horn and the underlying corium, which is especially thin at the tip of the toe, will be uncovered. Therefore this area is very vulnerable for ascending infections. An alternative treatment for cattle with thin soles was presented at the recent Lameness Conference in Bristol UK.
The greater the manure contamination of the lower leg, the more frequently cows should be foot bathed. While some farms with excellent leg hygiene may use a footbath only once a week, others must footbath 5-7 days per week.