A novel combination of fipronil and permethrin (Frontline Tri-Act®/Frontect®) reduces risk of transmission of Babesia canis by Dermacentor reticulatus and of Ehrlichia canis by Rhipicephalus sanguineus ticks to dogs

Abstract

BackgroundThe ability of Frontline Tri-Act®/Frontect®, a topical ectoparasiticide containing fipronil and permethrin for dogs, to prevent the transmission of Babesia canis as well as Ehrlichia canis was evaluated by infesting dogs with infected vector ticks.MethodsFor the Babesia canis study, 16 dogs were randomly allocated to two groups. Eight dogs were treated on day 0 with a topical spot-on formulation containing 6.76 % w/v fipronil plus 50.48 % w/v permethrin and eight dogs served as the untreated control group. Dermacentor reticulatus ticks, with a B. canis infection rate ranging between 2 and 10 %, were placed onto dogs on days 7, 14, 21 and 28. In situ tick counts were performed on Days 9, 16 and 23. Ticks were counted and removed on Day 30. Infection of the dogs with B. canis was monitored by rectal temperature readings, clinical examinations and blood smears as well as PCR and IFA (indirect fluorescent antibody assay).For the Ehrlichia canis study, another 16 dogs were allocated to two groups. Eight dogs were treated with the fipronil and permethrin combination on days 0 and 28 and eight dogs served as untreated controls. Rhipicephalus sanguineus ticks, carrying an infection rate of 13 % for E. canis, were released in the sleeping kennels of the dogs on days 7, 14, 21, 28, 35, 42, 49 and 56. Ticks were counted in situ on the dogs on a weekly basis. All ticks were removed and counted on the final assessment day 58. Infection of the dogs with E. canis was monitored by rectal temperature, clinical examinations, and testing of blood samples by PCR, IFA and platelet counts.ResultsB. canis was transmitted by D. reticulatus ticks to all eight untreated control dogs and to one treated dog, which was confirmed by blood smears, PCR and IFA. E.canis was transmitted by R. sanguineus ticks to all eight untreated control dogs. Two of the dogs in the treated group were found positive based on PCR and/or IFA.ConclusionsFrontline Tri-Act®/Frontect® significantly lowered the risk for dogs to acquire a B. canis infection by 87.5 % over a challenge period of 28 days. The risk for dogs to acquire E. canis was reduced by 75 % over a period of 56 days.

Canine Monocytic Ehrlichiosis: An Update on Diagnosis and Treatment

“…Importantly, it was recently shown that E. canis transmission may start a few (3-8) hours after tick attachment [95]. Tick control products such as those containing phenylpyrazoles (pyriprol, fi pronil), pyrethroids (permethrin, deltamethrin, tetramethrin, fl umethrin), amitraz and isoxazolines (fl uralaner, sarolaner, afoxolaner) have been shown to be very effective in reducing the incidence of E. canis infection and/or tick infestation, but the owners should be aware that no product can completely prevent the infection in all dogs, under all circumstances [96][97][98]. In highly endemic areas, when adequate tick control is hard to achieve, prophylactic daily use of low dose doxycycline during the tick season, reduces the risk of infection [99], although this practice may promote drug resistance.…”

Evaluation of the efficacy of sarolaner (Simparica®) in the prevention of babesiosis in dogs

“…The experimental infection model used in this study was previously developed and described for the evaluation of the prevention of B. canis transmission [ 15 – 17 , 19 , 20 , 25 ]. The advantage of an experimental model is that the challenge load can be standardized for all dogs [ 25 ], which is not the case under field conditions.…”

“…Several treatments are known to kill D. reticulatus ticks and reduce B. canis transmission. In addition to the topically applied contact acaricides [ 15 – 17 ], systemic isoxazoline compounds have been shown to prevent B. canis transmission [ 18 – 20 ]. The objective of the current study was to evaluate the efficacy of a single treatment with sarolaner (Simparica®; Zoetis) at the minimum recommended label dose of 2.0 mg/kg in the prevention of B. canis transmission when dogs are challenged with infected D. reticulatus ticks 21 and 28 days after treatment.…”

Eficácia da associação de fipronil e permetrina no controle de ctenocephalides felis felis e rhipicephalus sanguineus sensu lato em cães artificialmente infestados

“…Apesar da permetrina possuir ação inseticida e acaricida, sua persistência não é acentuada. Sua associação ao fipronil seria desejável pois acrecentaria ação repelente e efeito "knock-down", minimizando a possibilidade que que carrapatos e pulgas consigam se alimentar e prevenindo, desta forma, a transmissão de hemoparasitos como Babesia spp., Ehrlichia canis (Jongejan et al, 2015;.…”