The National Association of Cattle Foot Trimmers held its inaugural conference in central Liverpool, hosting speakers from both the UK and further afield. Laura Bowyer reports.
Cows with digital dermatitis should not be culled as they often are the highest yielders, was the message from Dr Arturo Gomez, dairy vet at Zinpro, at the recent National Association of Cattle Foot Trimmers conference.
But major production loses could be incurred by animals which contract the disease, particularly as heifers.
Dr Gomez said: “Animals infected as heifers will lose 335kg milk in their first lactation and if they get it as a heifer they are likely to get it again, as well as less problems around reproduction and the transition period.
He added digital dermatitis represented half of the lesions on housed cattle’s feet in the world, with these lesions being the main reservoirs of digital dermatitis bacteria, and if chronic cases were eliminated there would be no problems.
Suggesting less than 5 per cent formalin will correct most problems, Dr Gomez said a concentrate which was too strong could irritate the skin. “Footbathing should be made as consistent as possible. Evaluate it and if it is not working, try using another method based on the needs of the farm.”
Dr Nick Evans, senior lecturer in infection biology at the University of Liverpool, was also present at the conference and commented footbaths will stop new cases of digital dermatitis, but may not stop reoccurring problems.
He explained there was no single effective treatment for the condition, with footbaths such as lincospectin, tetracycline, formalin or copper sulphate and at present no effective vaccination. Although these should be useful in controlling the disease.
A topical oxytetracycline spray can be applied to the foot but this was likely to have only a temporary effect rather than full cure and the use of systemic antibiotics, which may have greater effect, were often not an option for cows in-milk. Treated animals commonly show the condition time and time again and can carry the disease into new farms if moved. Farm hygiene should also be improved to tackle outbreaks of the condition.
Dr Evans suggested foot trimmers had a part to play in cracking down on digital dermatitis too, but by definition their success was lower than someone who was at hand all the time who could get to cows quickly. He said the bacteria potentially can be passed from the gastrointestinal tract to the foot and also foot-to-foot through foot trimming equipment – if not disinfected between animals, and human hands or via the animals’ footprints.
Although disinfecting foot trimming tools will not fully stop the spread of the bacteria, Dr Evans’ studies showed it will help minimise the risk. He suggested using a two-knife system, where one knife disinfects while the other is being used, changing between foot. However, there were concerns from foot trimmers present of the safety of using wet knives.
In further explanation of the disease, Dr Evans said digital dermatitis was caused by at least three different species of treponemal bacteria.
He said: “These treponemes are not as fragile as we once thought and are likely to survive a couple of days in the slurry environment. Recent research from the USA suggests it takes at least three months from initial infection for a lesion to be seen. Previous research also demonstrates outbreaks can appear seasonally, with levels peaking in the winter at housing.”
Treponemes are difficult to grow, highly mobile bacteria which belong to the spirochete family and are known for their spiral cell shape. Digital dermatitis is considered to be caused by at least three different species of treponemal bacteria.
Recent research at the University of Liverpool further suggests it is the same three species of bacteria which can be found in different animal hosts (for example cattle and sheep) causing digital dermatitis.
These bacteria are not just the same bacterial species but the exact same strains, in some cases, shared between different host species such as cattle and sheep, suggesting there is actual transmission between these different animals.