Efficacy of an imidacloprid/flumethrin collar against fleas, ticks, mites and lice on dogs (Parasites & Vectors)

Background: The studies reported here were conducted to ascertain the efficacy of imidacloprid/flumethrinincorporated in a slow-release matrix collar, against infestations of dogs by fleas, ticks, mitesand lice. Efficacy was evaluated against the flea Ctenocephalides felis felis, the ticksRhipicephalus sanguineus, Ixodes ricinus, Ixodes scapularis, Dermacentor reticulatus andDermacentor variabilis, the mite Sarcoptes scabiei and the biting louse Trichodectes canis. Methods: Groups of collar-treated dogs (n = 7-10) were infested with fleas and/or ticks at monthlyintervals at least, over a period of up to 8 months. Efficacy against fleas was evaluated 24 to48 h after treatment and 24 h after each re-infestation. Efficacy against ticks was evaluated at48 h (acaricidal), 6 h (repellent) and 48 h (sustained) after infestation. The effect of regularshampooing or immersion in water on the efficacy of the collars was also tested. Efficacyagainst flea larvae was assessed by incubating blanket samples after dog contact with viableflea eggs. Effectiveness against lice and mites was evaluated after treatment of naturallyinfested animals. With the exception of the mites, efficacy was calculated by comparisonwith untreated negative control groups. Results: Efficacy against fleas (24 h) generally exceeded 95%, and against flea larvae it exceeded 99%for 8 months. Sustained acaricidal (48 h) efficacy, covering a period of 8 months was 100%against I. ricinus, starting 2 days after treatment (in vivo), and 100% against I. scapularis (invitro), above 97% against R. sanguineus, generally above 97% against D. reticulatus andabove 90% for D. variabilis.Repellent (6 h) efficacy 2 days after treatment and continuing for 8 months was consistently100% against I. ricinus, and above 90% against R. sanguineus.Regular shampooing affected efficacy against fleas and ticks to a lesser extent than regularimmersion in water.The collars eliminated Trichodectes canis within 2 days and Sarcoptes scabiei within 3months. Conclusion: The rapid insecticidal and acaricidal properties of the medicated collars against newlyacquiredinfestations of fleas and ticks and their sustained high levels of preventive efficacyhave been clearly shown. Consequently they have the potential to prevent the transmission ofvector-borne diseases and other conditions directly associated with infestation throughout anentire season of parasite abundance.