Year-round efficacy of a single treatment of fluralaner injectable suspension (Bravecto Quantum™) against repeated infestations with Rhipicephalus sanguineus (sensu lato) and Ctenocephalides felis in dogs

BACKGROUND: Poor owner compliance with monthly control measures means that dogs in Australia can remain susceptible to infestations with fleas, present throughout the whole year, and brown dog ticks, which thrive in tropical and subtropical areas. A 150 mg/ml injectable fluralaner suspension (Bravecto Quantum™) was developed to help ensure year-round protection against these parasites. A study investigated the persistent efficacy of this formulation against repeated challenges with Rhipicephalus sanguineus (sensu lato) and Ctenocephalides felis throughout 12 months following a single subcutaneous treatment. METHODS: Twenty dogs were blocked by pre-treatment R. sanguineus s.l. counts and randomized to an untreated control group or to a group treated once, on day 0, with the fluralaner injection (15 mg/kg). Infestations of 50 mixed-sex, unfed adult R. sanguineus s.l. and up to 100 C. felis were done on days 7, 14, 35, 63, 91, 126, 154, 182, 210, 245, 273, 301, 336 and 365. Live flea and tick counts were completed 48 h post-infestation. Flea infestations were also done on day −1, with counts on day 2. Infestations were considered adequate if at each evaluation, at least six dogs in the control group retained at least 20% of tick challenges and 25% of flea challenges. RESULTS: The fluralaner injectable suspension was well tolerated. Efficacy against existing flea infestations was > 99% (arithmetic and geometric means) at 48 h post-treatment. At all subsequent assessments throughout the year following treatment, efficacy against fleas remained at 100%. Arithmetic mean tick count reductions relative to the control group ranged from 97.6% to 100% from day 7 through 11 months and was 92.6% at 12 months (geometric means 95.2% to 100% through 12 months). CONCLUSION: The injectable fluralaner suspension was effective against fleas and brown dog ticks for 12 months following a single treatment. Compared with more frequently administered products where compliance may be suboptimal, the year-round efficacy of this veterinarian-administered fluralaner formulation has the potential to improve owner compliance for control of fleas and ticks. In turn, by reducing the detrimental effects of flea and tick infestations and risk of transmission of flea- and tick-borne pathogens, canine health can be enhanced. GRAPHICAL ABSTRACT: