Prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs after topical administration of fluralaner spot-on solution

Abstract

BackgroundThe preventive effect of fluralaner spot-on solution against transmission of Babesia canis by Dermacentor reticulatus ticks was evaluated.FindingsSixteen dogs, tested negative for B. canis by polymerase chain reaction (PCR) and immunofluorescence assay test (IFAT), were allocated to two study groups. On day 0, dogs in one group (n = 8) were treated once topically with fluralaner spot-on solution (Bravecto™ Spot-on Solution) according to label recommendations and dogs in the control group (n = 8) remained untreated. On days 2, 28, 56, 70 and 84, all dogs were infested with 50 (±4) D. reticulatus ticks harbouring B. canis, with tick in situ thumb counts 48 ± 4 h after each infestation. On day 90, ticks were removed from all dogs and counted. Prior to each infestation, the presence of B. canis in the respective tick batch was confirmed by PCR, and 12–16 % of ticks were found to be infected with B. canis. Efficacy against ticks was 99.5 and 99.3 % on days 4 and 58 after treatment, respectively and 100 % on all other days. Replacement dogs were included for any B. canis infected control dog (in total 19). All control dogs (n = 27) became infected with B. canis, as confirmed by PCR, performed every 7 days, and by IFAT, performed every 14 days after treatment. None of the eight treated dogs became infected with B. canis, as they were tested negative by PCR and IFAT throughout the study until day 112. By comparing infected dogs in the treated group with infected dogs in the untreated control group, a 100 % preventive effect against B. canis transmission was demonstrated.ConclusionsA single topical administration of fluralaner spot-on solution effectively prevented the transmission of B. canis by infected D. reticulatus ticks over a 12-week period.

Blocking Transmission of Vector‐borne Diseases

“…transfer. In this context, fast-acting ectoparasiticides could be effective at preventing disease transmission in ticks (Reichard et al, 2013;Fourie et al, 2013a;Brianti et al, 2014;Jongejan et al, 2015;Beugnet et al, 2014;Honsberger et al, 2016;Taenzler et al, 2016). In soft ticks (Argasidae), also referred to as softbacked ticks, pathogens face similar conditions as in hard ticks (i.e.…”

“…Maurin and Raoult, 1999 Tsetse flies (Glossinidae) disease transmission of hard tick pathogens that are not immediately passed on to the host such as Babesia sp Taenzler et al, 2016) or Borrelia sp. (Honsberger et al, 2016).…”

“…Therefore, requirements for new ectoparasitic drugs should include not only the control of ectoparasites for a certain period of time, but also address their ability to block the transmission of the various vector-borne pathogens by a rapid onset of action. In this scope, "speed of kill" has become an important commercial differentiator for recent marketed products Wengenmayer et al, 2014;Beugnet et al, 2016;Blair et al, 2016; and many studies have been designed for testing the ability of those products to block transmission of some important pathogens of cats like Bartonella henselae (Bradbury and Lappin, 2010), and of dogs like Dipilidium caninum (Fourie et al, 2013a), Leishmania infantum (Brianti et al, 2014), Ehrlichia canis (Jongejan et al, 2015), Borrelia burgdorferi, Anaplasma phagocytophilum (Honsberger et al, 2016), and Babesia canis Taenzler et al, 2016). These studies all report a complete prevention of pathogen transmission by fast elimination of the vector.…”

Prevention of transmission of Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum by Ixodes spp. ticks to dogs treated with the Seresto® collar (imidacloprid 10% + flumethrin 4.5%)

“…collars, spot-ons and orals) and modes of action (contact vs. systemic efficacy) (e.g. Elfassy et al 2001;Fourie et al 2013a;Honsberger et al 2016;Spencer et al 2003;Taenzler et al 2015Taenzler et al , 2016.…”

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

“…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.…”