Repellency and acaricidal efficacy of a new combination of fipronil and permethrin against Ixodes ricinus and Rhipicephalus sanguineus ticks on dogs

Abstract

BackgroundA blinded, controlled laboratory study was conducted to assess the repellency and acaricidal activity of a topical spot on formulation, a combination of fipronil and permethrin, against Ixodes ricinus and Rhipicephalus sanguineus ticks on dogs.MethodsA group of 16 adult mixed breed dogs were randomly divided into treatment and control groups based on pre-treatment live tick counts. On Day 0, the topical spot on formulation of fipronil + permethrin (commercialized under the name Frontline Tri-Act®/Frontect®) was administered to dogs in the treatment group at the minimum recommended dose of 0.1 mL/kg, corresponding to 6.76 mg fipronil/kg and 50.48 mg/kg permethrin. Tick infestations were performed with I. ricinus (50 females, 50 males) and R. sanguineus (25 females, 25 males) on each dog on Days 2, 7, 14, 21, and 28. Dogs were sedated prior to exposure and confined to crates for approximately 4 h following tick challenge. Ticks were released next to the sedated dogs and tick counts were performed at 4 h and 24 h after the start of exposure for tick counts and removal.ResultsRepellency at 4 h against I. ricinus was 72.6, 96.3, 92.8, 89.0, and 88.7 % on Days 2, 7, 14, 21, and 28, respectively. Repellency was 100 % 24 h after exposures on Days 2, 7, and 14 and 99.6 % after exposures on Days 21 and 28. For R. sanguineus, repellency at 4 h was 78.0, 96.8, 91.5, 88.0, and 56.8 % on Days 2, 7, 14, 21, and 28, respectively. Repellency at 24 h was 98.6, 100, 98.7, 96.1, and 95.1 % for exposures on Days 2, 7, 14, 21, and 28, respectively.For I. ricinus, acaricidal efficacy recorded at 4 h was ≥ 91.1 % during the full month and was ≥ 99.5 % for the full month when counted at 24 h. Acaricidal efficacy against R. sanguineus was ≥ 94.7 % at 4 h from Day 2 to Day 21 and was 71.4 % on Day 28. Acaricidal efficacy at 24 h, was > 97.7 % during the month. Tick counts were statistically significantly reduced in treated dogs at all time-points during the study.ConclusionsA combination of fipronil and permethrin was highly effective at rapidly repelling and killing both I. ricinus and R. sanguineus ticks on dogs for at least 4 weeks, with a significant effect at 4 and 24 h after tick exposure.

Anti‐feeding and insecticidal efficacy of a topical administration of dinotefuran–pyriproxyfen–permethrin spot‐on (Vectra® 3D) on mice against Stegomyia albopicta (= Aedes albopictus)

“…In veterinary medicine, target species such as dogs are often involved in parasiticide testing without preliminary efficacy assessments in animal models (Tiawsirisup et al, 2007;Machida et al, 2008;Bonneau et al, 2010;Franc et al, 2012;Molina et al, 2012;Dumont et al, 2015aDumont et al, , 2015bVarloud & Hodgkins, 2015). However, these models can provide preliminary and complementary information that may be useful in further testing on the targeted animal.…”

Data collection for risk assessments on animal health (Acronym: DACRAH) : Final Report

“…External usetopic/spray A combination of 6.76% fipronil and 50.48% permethrin offered an efficacy of 0.97 30 days post-treatment (Dumont et al, 2015c) A combination of 6.76% fipronil and 50.48% permethrin offered a repellency at 24h of 95% 28 days post-treatment (Varloud and Fourie, 2015) 5 out of 8 dogs treated with a combination of fipronil (9.8 %) and (S)-methoprene (8.8 %) had ticks 28 days post-treatment (Varloud and Hodgkins, 2015) A combination of fipronil (9.8 %) and (S)-methoprene (8.8 %) offered an efficacy of 0.86 106 post-treatment (Tiawsirisup et al, 2013) Fipronil (10%) had an efficacy of 0.9 28 days post-treatment (Kuzner et al, 2013) Fipronil had mean efficacy of 0.94 30 days post-treatment (Kunkle et al, 2012b) A combination of Fipronil/Amitraz/ (S)-Methoprene had a mortality effect (48h postexposure) of 0.99 2 days post-treatment The efficacy of a combination containing fipronil, amitraz and (S)-methoprene increased from 0.85 on day of treatment (mortality recorded 24h post-exposure) to 0.91 50 days later. (Brianti et al, 2010) A combination of fipronil 10% + (S)-methoprene 9% had an efficacy of 0.93 28 days post-treatment Fipronil had an efficacy of 0.89 42 days posttreatment (Hellmann et al, 2007) Fipronil had an efficacy of 0.89 56 days posttreatment (Hellmann et al, 2003) Fipronil had an efficacy of 0.89 28 days posttreament (Beugnet et al, 2016) combination of fipronil and permethrin had efficacy of 0.98 (tick mortality 24 hours postexposure)28 days post-treatment Amitraz EC 251-375-4 (Kunkle et al, 2012b) Substance is very toxic to aquatic life, is very toxic to aquatic life with long lasting effects, is harmful if swallowed, may cause damage to organs through prolonged or repeated exposure and may cause an allergic skin reaction.…”

“…External usetopic/spray A combination of 6.76% fipronil and 50.48% permethrin offered an efficacy of 0.99 30 days post-treatment against I. ricinus (Dumont et al, 2015c) A combination of 6.76% fipronil and 50.48% permethrin offered a repellency at 24h against I. ricinus of 99% 28 days post-treatment (Carithers et al, 2015) fipronil/(S)-methoprene/cyphenothrin offered an efficacy of 0.99 against I. scapularis 28 days post-treatment The efficacy of a combination of fipronil/amitraz/(S)-methoprene decreased from 0.99 on day of treatment to 0.57 43 days later. (Bonneau et al, 2010) A spot-on solution of 10% fipronil had a mean efficacy of 0.92 against I. ricinus 30 days posttreatment (Hellmann et al, 2007) Fipronil had an efficacy of 0.82 56 days posttreatment (Hellmann et al, 2003) Fipronil had an efficacy of 0.69 28 days posttreatment (Endris et al, 2002) Efficacy against I. ricinus decreased from 0.61 2 days post-treatment to 0.16 41 days posttreatment Amitraz EC 251-375-4 Substance is very toxic to aquatic life, is very toxic to aquatic life with long lasting effects, is harmful if swallowed, may cause damage to organs through prolonged or repeated exposure and may cause an allergic skin reaction External usetopic/spray…”

“…External usetopic/spray (Varloud and Fourie, 2015) 4 out of 8 dogs treated with a combination of dinotefuran, pyriproxifen and permethrin still had ticks 29 days post-treatment (Varloud and Hodgkins, 2015) A combination of dinotefuran, pyriproxifen and permethrin offered an efficacy of 0.93 106 post-treatment (Dumont et al, 2015c) A combination of 6.76% fipronil and 50.48% permethrin offered a repellency at 24h of 95% 28 days post-treatment (Hellmann et al, 2003) A combination of Imidacloprid 10%/Permethrin 50% had an efficacy of 0.98 28 days post treatment (Varloud and Fourie, 2015) 1 out of 8 dogs treated with a combination of dinotefuran (4.95 %), pyriproxifen (0.44 %), and permethrin (36.08 %) had ticks 15 days post-treatment Dinotefuran EC 605-399-0 (Varloud and Fourie, 2015) Substance is very toxic to aquatic life, is very toxic to aquatic life with long lasting effects and is harmful if swallowed.…”

“…Biocide type 18* (Dumont et al, 2015c) harmful if swallowed, harmful if inhaled and may cause an allergic skin reaction A combination of 6.76% fipronil and 50.48% permethrin offered a repellency at 24h against I. ricinus of 99% 28 days post-treatment (Epe et al, 2003) A combination of Imidacloprid 10%/Permethrin 50% had an efficacy of 0.92 37 days post treatment (Hellmann et al, 2003) A combination of Imidacloprid 10%/Permethrin 50% had an efficacy of 0.96 28 days post treatment (Endris et al, 2002) Efficacy of Permethrin 65% against I. ricinus decreased over time from 0.99 2 days posttreatment to 0.48 41 days post-treatment Fipronil EC 424-610-5 (Dumont et al, 2015a) Substance is fatal if inhaled, is toxic if swallowed, is toxic in contact with skin, causes damage to organs through prolonged or repeated exposure, is very toxic to aquatic life and is very toxic to aquatic life with long lasting effects.…”