Beware virulent foot-rot, flockmasters are warned
Beware virulent foot-rot, flockmasters are warned
By Emma Penny
FLOCKMASTERS are urged to check lame sheep for a virulent form of foot-rot.
The disease, which causes crusting lesions around the hoof coronet and between the toes, is being researched by vet investigation centres, which report its occurrence in Vet Record (Jan 31, 1998).
According to Brian Preece, senior vet officer at the Starcross VI centre, Devon, investigation is still in the early stages. "We have had reports of more virulent foot-rot from a few flocks over the past four to five months, and have either visited, sampled or obtained anecdotal evidence from 12 flocks.
"Information so far suggests the disease is similar to bovine digital dermatitis, although it may be related to mild, wet winter weather," he says.
All flocks reported unusually severe damage round the coronet – the hoofs growing point. When the coronet and underlying tissues are separated – as has happened in some of these cases – the horn will come off, while in one case infection caused skin loss above the coronet.
Foot-rot usually occurs only when two bacteria work together. But only one of these is found in the new cases, while a spiral-shaped bacteria, which is also seen in bovine digital dermatitis, is present.
The disease has also been found where flocks regularly footbath in formalin or zinc sulphate.
Mr Preece urges producers with lame sheep to examine their flocks to establish the cause. "Is it scald, foot-rot, or something else? Some flocks may be affected by all three, but where virulent foot-rot is a concern there is little trouble in recognising it – it is quite unlike anything most producers have seen before."
Where sheep are infected, the vet should be called in. "Vet Investigation centres are also interested to hear of more cases, but this has to be done through your vet."
Like bovine digital dermatitis, antibiotic treatment is the only cure. Tetracycline spray is effective in cattle, but it is far easier to stand sheep in an antibiotic foot bath, he says.
"But feet must be clean before footbathing; there is no point in spending money on expensive treatment which has little effect because feet are too dirty."
Although the best option is to wash feet before footbathing, Mr Preece acknowledges that few producers will be prepared to do this, and suggests penning sheep on a hard-standing to help remove mud before treatment. *
VIRULENT FOOT-ROT
• Crusting round coronet.
• Severe hoof damage.
• Antibiotics required.