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 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.
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.
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.
Users of Hoof Supervisor® (HS) lesion recording software have an excellent pictorial, touch-screen based system for selecting hoof lesions, based on the claw zone where they appear. For others wanting to identify and deal with a lesion they see on inspection of a hoof, a web-based lesion selector similar to that used in the HS system will be helpful.
To assist trimmers to more consistently score lesion severity, Alberta hoof trimmers have created a Lesion Severity Scoring Guide containing example photos of each of 3 severity scores for 14 lesions.
A study by researchers at Cornell University examined the association between claw horn lesions and the thickness of the digital cushion. Results suggest that thin digital cushions, related to low body condition score, may be a factor in the development of sole ulcers and white line lesions.
To investigate the association between locomotion score and the presence of hoof lesions, researchers examined 10,699 cows from 91 dairy herds in southern Chile. Locomotion score was recorded on a scale of 1-5 using the Sprecher system. Lesions were recorded by observation of all four feet with each cow standing in a metal crush. Locomotion scoring was a relatively insensitive method for the detection of some important claw lesions.
Dr. Dörte Döpfer at the University of Wisconsin, describes the dynamics of digital dermatitis infection as a cycle with 6 distinct stages.