Foot trimmers and veterinarians could be responsible for spreading cattle lameness from cow to cow due to improper hoof knife disinfection, early research suggests.
Studies at the Department of infection biology at the University of Liverpool have found that treponemes, the bacterial agent of digital dermatitis, can survive on the hoof knife.
Rinsing the knife in disinfectant was tested as part of the study. Around 30 per cent of knives were still positive for infection after being quickly washed and wiped on a paper towel, in a manner similar to a brisk onfarm wash.
However, Roger Blowey, a cattle lameness expert involved in the study with Leigh Sullivan, remains tentative, stating that the study is scheduled to conclude in 2015 and is still in early stages.
“I can’t say it is a major vector but I can clearly state that the hoof knife represents a risk,” said Mr Blowey.
Digital dermatitis first came into the UK in 1985 and, according to Mr Blowey, is now responsible for 30 per cent of all cow lameness in the UK. In this time digital dermatitis expanded from a simple skin infection to an infection penetrating inside the hoof.
But veterinary and scientific communities are yet to figure out how the condition spreads from cow to cow.
“It can’t be found in the slurry or the environment, but data consistently shows that digital dermatitis can be found on affected feet and swabs taken from the hoof knife blade,” said Mr Blowey.
“When a cow’s foot becomes under run, pus becomes trapped and the hoof knife is used to remove the whole of the sole of the foot to expose the corium.
“Our hypothesis therefore, is that when farmers are using a hoof knife, if the hoof knife is carrying a digital dermatitis infection and the knife is in contact with the corium, the infection is being directly introduced to the corium.”
This ground-breaking theory could drastically alter on farm trimming routines the world over.
Near Picture: Example of digital dermatitis Topmost Picture: Necrotic toe after trimming Bottom picture: Roger Blowey and a boiled-up hoof from a chronically lame cow
Photos Courtesy of Roger Blowey
Until 2011, New Zealand had a reputation for being digital dermatitis free but over the past two years has spread into the New Zealand dairy herd.
New Zealand lameness expert Neil Chesterton is of the opinion that this is the type of lateral thinking that is required to beat the digital dermatitis condition.
“Because this is a new problem it requires new solutions. I would never have considered that something so basic like a hoof knife could be spreading digital dermatitis,” said Mr Chesterton, a North Island veterinary surgeon from Taranaki. “Something simple like clean your knife with antiseptic between cows could make a difference.”
Five cases were initially reported in New Zealand in 2011. Two years later and non-healing lesions and digital dermatitis represents a considerable threat to the dairy industry.
"Heifers were being introduced into the herd and time after time being cut down with lameness and digital dermatitis"
Further afield, rising cases of non-healing lesions in lame cows is causing concern in Chile, Uruguay and Argentina. South American herds are further proof that cattle lameness is a growing problem in pasture based systems as well as more intensive housed herds.
Mr Chesterton investigated one herd of 780 cows in Chile where he reported 200 lame cows, with around two thirds affected with ‘non-healing problems’.
Some think intensive indoor housing is allowing digital dermatitis to become established but Mr Blowey has posited that it is not necessarily a question of intensification, but one of hygiene.In one area of the country farming 19,000 cows, approximately 1700 were lame. Mr Chesterton linked this problem with the development of digital dermatitis, first seen in Chile in 2006.
He warns that unhygienic environments, lack of foot-bathing, failure to feet treat promptly and poor management of dry cows are not errors exclusive to intensive farms. Furthermore, Mr Blowey has witnessed these problems wherever lameness is a major herd health concern.
With little in the way of cure, control is the only tool available and one answer is to regularly footbath cows with disinfectants/antiseptics to control lameness problems within a herd.
Mr Chesterton has advised farmers in Chile to build footbaths no more than three metres long and to do away with water baths to clean feet beforehand as this is a catalyst for cow excretion and leads to dung in baths.
Gloucestershire farmer, James Griffiths has successfully reduced digital dermatitis from being a major issue to a rare surprise by working alongside Mr Blowey.
“Through the nineties we were expanding the herd and naively bought in heifers without considering the disease implications,” admits Mr Griffiths. “This developed into a big problem.”
“Heifers were being introduced into the herd and time after time being cut down with lameness and digital dermatitis.”
Over a period of ten years Mr Griffiths learned that, through daily foot-bathing with a 5 per cent Foramalin solution, lameness cases could be reduced significantly.
He has urged fellow farmers to treat the issue like mastitis and foot-bath all cows daily, just like teat dipping. Equally as important is making sure everyone is working together to properly implement a simple foot health plan.
“The golden rule is to keep it simple with everyone reading from the same page. Everyone on the farm knows about cows’ feet and the hoof trimmer and vet can talk to relief milkers and stockmen and have a conversation about digital dermatitis and lameness,” said Mr Griffiths.
Current thinking is to treat the condition like mastitis and bathe feet every milking, like teat dipping. Dry cows and precalving heifers should also be foot bathed if housed in a yard.
Mr Blowey, added: “Just like with mastitis, you prevent digital dermatitis by paying attention to the environment, making sure that sheds are clean and dry and you regularly footbath, twice a day every day at milking, to prevent any infection spreading.”
Speaking from experience, Mr Griffiths has learnt that a vigilant approach and simple daily routine can control digital dermatitis.
Mr Griffiths concluded: “There are very few things in agriculture where you can say, if you try this it will work for you, but regular foot bathing the whole herd will bring results.”