TOPICAL PYRIPROXYFEN FOR CONTROL OF THE CAT FLEA AND MANAGEMENT OF INSECTICIDE RESISTANCE

This study sought to evaluate the residual ability of BreakthruI(R) IG R Stripe-On to control the development of adult fleas, larvae, and pup ae from the egg stage. Within each gender based group, cats were ranke d by pretreatment emergent flea larvae counts and allocated randomly t o one of two treatment groups of 6 cats each. Cats allocated to the tr eatment group were treated on test day 0 with BreakthruI IcR Stripe-On at a rate of 1.5 mt per cat. Untreated control cats were not medicate d. Cats were infested with fleas for the purpose of determining ovicid al activity larvicidal activity and inhibition of adult emergence on d ays 0, 42 56, 84, and 103. Seventy-two hours after each flea infestati on, 100 healthy appearing Ctenocephalides felis eggs were collected wh en possible, and incubated at 80 degrees F and approximately 80% relat ive humidity. Eggs were scored for percentage successful larval emerge nce after 72 hours incubation. After counting the number of hatched la rvae they were returned to the incubator for completion of development to the adult stage. Thirty-five days after each egg collection the nu mber of pupae and emergent or pre-emergent adult fleas was recorded. O vicidal activity, larvicidal activity and inhibition of adult emergenc e were determined after normalization of treatment group counts by con trol group counts according to Abbott's formula. All cats tolerated Br eakthruI IcR Stripe-On application well, with no signs of systemic tox icity or local inflammation. BreakthruI IcR Stripe-On achieved complet e (100%) egg hatch inhibition for at least 46 days after treatment Con trol in excess of 96% was observed for at least 60 days, and control g reater than 88% was observed for at least 88 days. Control fell below 70% at the last evaluation on test day 107 Inhibition of larval pupati on and adult development mirrored results for flea egg hatch. Control was 100% for at least 46 days after treatment, above 96% for at least 60 days, and greater than 88% for at least 88 days. Control fell below 70% at the final evaluation on test day 107.