Efficacy of slow-release collar formulations of imidacloprid/flumethrin and deltamethrin and of spot-on formulations of fipronil/(s) - methoprene, dinotefuran/pyriproxyfen/permethrin and (s) –methoprene/amitraz/fipronil against Rhipicephalus sanguineus and Ctenocephalides felis felis on dogs

BACKGROUND: Two studies evaluating the efficacy of an imidacloprid/flumethrin collar (SerestoW, Bayer Animal Health, IVP), a deltamethrin collar (ScaliborW, MSD, CP1), a fipronil/(s)-methoprene spot-on (Frontline ComboW, Merial, CP2), a dinotefuran/pyriproxyfen/permethrin spot-on (Vectra 3DW, Ceva, CP3) and an amitraz/fipronil/(s)-methoprene spot-on (CertifectW, Merial, CP4/CP5) against repeated infestations with Rhipicephalus sanguineus and Ctenocephalides felis felis on dogs were conducted over periods of 226 days and 71 days respectively. METHODS: The first study comprised 4 groups of treated dogs and one untreated control group, and the second 3 groups of treated dogs and one control group. Each group consisted of 8 dogs. All dogs were infested with ticks and fleas at regular intervals. Ticks were counted 6 h, 18 h or 48 h after infestations and fleas 24 h after infestations. Efficacies of the treatments were calculated by comparison with the untreated control groups using standard descriptive statistics. RESULTS: The protective 48 h tick efficacy was 97.8% to 100% for the IVP (226 days), 69.3% to 97.4% for CP1 (170 days), 99.6% to 43.4% for CP2 (35 days) and 98% to 61.4% for CP3 (35 days). The protective 18 h tick efficacy was 98% to 99.6% for the IVP (71 days), 100% to 86.5% for CP4 (29 days), 100% to 72.8% for CP4 after re-treatment (35 days) and 98.8% to 54.3% for CP5 (35 days). The protective 6 h tick efficacy was 85.6% at Day 7 and 90.1% to 97.1% from Day 14 onwards for the IVP (70 days), 92.3% to 70.7% for CP4 (35 days), 97.5% to 65.2% for CP4 after re-treatment (35 days) and 95.1% to 51.8% for CP5 (35 days). The protective 24 h flea efficacy was 99.5/90.9% to 100% for the IVP (71/226 days), 66.7% to 83% for CP1 (170 days), 100% to 88.5% for CP2 (35 days), 100% to 73.3% for CP3 (35 days), 100% to 98.7% for CP4 (35 days), 100% to 87.5% for CP4 after re-treatment (35 days) and 100% to 79.5% for CP5 (35 days). CONCLUSIONS: These data suggest that the long-term efficacy provided by a medicated collar that is effective, is a means to overcome the fluctuating efficacy of spot-on treatments resulting from a lack of pet owner re-treatment compliance, and consequently protect animals successfully against ectoparasites and probably vector-borne diseases.