Lameness is top of the list of greatest threats to sheep health and welfare, according to a recent Moredun survey of sheep farmers. This ranks more of a problem than worms, enzootic abortion and other health issues, Schering Plough’s Paul Williams told producers attending an EBLEX Better Returns Programme workshop at Duchy College, Cornwall..
“Consequences of lameness are more far reaching than just the time spent treating animals,” he added. “Ewes are affected in terms of reduced fertility, poor milk production and increased incidence of twin lamb disease, whereas for lambs, delayed finishing and being unfit to travel are major factors.”
To tackle lameness, it is crucial diagnosis is correct before treatment commences. “If producers have spent time combating what they think is footrot, when actually the problem is contagious ovine digital dermatitis, it’s not only time, but money which is lost.”
Examine cases of lameness carefully before deciding on a treatment, said vet George Henry of Castle Vet Group. “There are four main causes of lameness, with several other less common ones. Scald, footrot, CODD and white line disease are the key four, with interdigital hyperplasia, pedal joint sepsis and toe granuloma factoring in too.”
With CODD becoming more prevalent in the UK sheep flock, watching for signs is key to early diagnosis. “Signs include separation at the skin/horn junction and eventually lead to the horn detaching completely from the foot. Antibiotic treatment is required to treat CODD and to prevent the bacteria taking hold in your flock quarantine replacements for a minimum of three,” he said.
With the recent rain and warm weather, scald is sure to feature highly on producer hit lists. Long, wet grass and thistles can exacerbate the problem, so good pasture management is important to control the condition. Caused by bacteria commonly found in sheep dung, scald is found between toes where skin often looks oozy and irritated. “Footbathing, topical antibiotics, such as terramycin spray, and liming gateways and areas around troughs are all methods of controlling and treating scald,” he added.
Footrot is characterised by its name, often starting at the back of the foot and moving forwards, running under the horn of the sole and hoof wall, rotting the hoof. “There are 10 strains of footrot the bacterium, Dichelobacter nodosus, which often work alongside the scald bacterium, and cases are more common in spring and autumn,” said Mr Henry.
An essential point to consider when targeting treatment is that footrot bacteria only survive on the soil for seven to 10 days and are carried from year to year by animals, explained Mr Williams. “Tackling footrot has to be targeted as a flock, rather than individually. A strategic approach to controlling footrot should ideally start with the whole flock being examined, with those sheep with footrot being separated from the flock and those without put onto grazing which hasn’t been pasture for a minimum of two weeks.”
Once those infected have been separated, regular footbathing in zinc sulphate and targeted antibiotic treatment can help get on top of the problem before returning cured animals to the flock. “Treatment should be repeated for at least five to seven days, with any still showing signs culled and not included in the flock again as these are the animals which reinfect.”