7 August 1998

Isolation pays with your replacements

AVOID unwittingly purchasing disease into your flock this autumn, and ensure replacement ewes and tups are isolated before joining the flock.

Speaking at Sheep 98 last week, Oxon sheep vet Chris Trower said that buying disease into a flock was easy as it was not always apparent at sales.

Among the newer threats to flock health are caseous lymphadenitis (CLA) and virulent foot-rot, he warned.

"We are seeing a lot more CLA. It appears to be more prevalent in pedigree flocks. People often put lesions down to lumps and bumps but they could be the result of CLA infection, which is not treatable," he cautioned.

The infectious disease is a major threat to flocks. "It is difficult to tell if an animal is infected, but be suspicious when buying sheep – it may not just have a boil."

Virulent foot-rot, which has also just been discovered in flocks, is another disease to be wary of when buying-in, warned Liverpool University sheep vet Agnes Winter.

"This is caused by the same organism as scald and foot-rot, but its much more serious. When its not caught early enough and treated promptly, the entire foot falls off, while skin above the foot is also affected."

Like foot-rot, it is contagious and infectious. "Avoid buying lame sheep at market – inspect and isolate replacements for two to three weeks before they join the flock. Where it is suspected, treat as soon as possible," said Dr Winter.