A NOVEL DIP FORMULATION OF A SYNTHETIC PYRETHROID (SP) FOR THE CONTROL OF BLOWFLY MYIASIS OF SHEEP

Field trials were carried out during the summer months of 1994 and 199 5 to ascertain the prophylactic effects of a 10% w/w formulation of a synthetic pyrethroid (Ecofleece, Cross Vetpharm Group Ltd.) against sh eep blowfly myiasis (fly strike). The trials were carried out on the s ame three farms each year. The flocks, of mixed breeds, comprised betw een 500 and 700 sheep, Treated sheep which consisted of ewes and lambs were plunge dipped, with at least one complete immersion. At least 10 % of each flock were left untreated to act as sentinels. Both sentinel and treated sheep mixed freely at pasture, All recorded cases of fly myiasis were treated by topical applications of the same formulation. Inspections of the flocks were made daily by the farmers and weekly by one of the investigators. Prophylaxis against blowfly myiasis was ach ieved for periods ranging from 3 to 9 weeks. On some occasions, fly la rvae developed in faecal dags but failed to establish on the sheep or cause lesions.