24 October 1997

Worm drugs could be cut by targeting

TARGETED treatment of wormy sheep, super-drugs, and fungi could help reduce use of wormers and risks of anthelmintic resistance.

Speaking at the IGA conference, Peter Torgerson of the department of parasitology, University College Dublin, said selective treatment of wormy individuals would help cut anthel-mintic use. "About 10-20% of the flock carry most of the parasites and produce most of the contamination on pastures. If we could identify and treat only these sheep we could ensure the same level of control achieved by treating the entire flock," he said. The benefits would be reduced selection pressure and less risk of anthelmintic resistance.

Another method of parasite control would be to use a super avermectin. "Trials are already underway with such products – and their use could mean animals would only need treating once a year."

Some researchers were also investigating use of fungi which destroy the parasites in the dung before they have a chance to contaminate the pasture. "Animals are dosed with spores which colonise the faeces – trials suggest these fungi have real potential in the fight against anthelmintics," he said.