3 November 1995

Ivomec worries are unfounded

CONSERVATIONISTS fears over the use of ivermectin, a leading antiparasitic drug, have been rejected by manufacturers.

MSD Agvet, which markets ivermectin under the trade name Ivomec, claim there is "little foundation" for concerns that the product may be reducing the insect food available for some rare birds.

But Peter Newbery, of the Royal Society for the Protection of Birds, told a MSD Agvet meeting that the RSPB preferred to adopt a cautious approach towards the use of ivermectin on cattle grazing its reserves.

It is concerned over the indirect effect of the product on the chough, a rare bird mostly confined to the cliffs of western Britain. The chough feeds on insects taken from pastures and dung within about 1-2km of its nest site.

MSD calculates that less than 1% of all dung excreted by the UKs national herd during the grazing season contains ivermectin.

Some insects, mostly larvae, are reduced in number after exposure to ivermectin. But when evaluated under practical farm conditions, MSD Agvet claims any effects are localised and temporary. &#42