Digital dermatitis may not be spread through slurry, according to findings from the University of Liverpool.
“Our findings have failed so far to identify digital dermatitis in slurry,” says Stuart Carter, professor of vet pathology.
Digital dermatitis is caused by treponemes, organisms that are spread by foot-to-foot transmission. This explains why incidence is lower when cows are at grass.
The fact remains that farms that scrape more efficiently have fewer cases of digital dermatitis. “Although treponemes have not yet been found in slurry, the bacteria in muck irritates the problem and makes lesions more severe, so effective spraping is essential.”
Research shows treponemes attack the feet via the hair follicle. “The skin on the feet is extremely tough,” Mr Carter continues. “Foot hairs act as a weak spot for treponeme entry.”
Digital dermatitis is also complicating the treatment of other classic diseases. “We have noticed that older diseases such as toe necrosis or sole ulcers are getting worse and are becoming harder to treat. Ultimately, the digital dermatitis bug is the main cause.”
Liverpool University has isolated three strains of treponemes. “We know a lot about the organisms involved and how they spread from foot to foot. The next step is knowing how we can control it,” says Mr Carter.