A randomized, blinded, controlled USA field study to assess the use of fluralaner topical solution in controlling canine flea infestations

BACKGROUND: Orally administered fluralaner effectively controls fleas and ticks on dogs for 12 weeks. This study evaluates the flea control efficacy achieved with topically applied fluralaner in dogs. METHODS: This investigator-blinded, multi-center randomized, positive controlled study evaluated flea control efficacy in dogs following a single owner-applied treatment of topical fluralaner. A positive control group received three treatments, at 4-week intervals, of a commercial formulation of fipronil/(S)-methoprene. All dogs in households randomized to the fluralaner group were dispensed an initial treatment at enrollment and a second treatment at week 12 for an additional 3-week observation of treatment safety. Households with up to five healthy dogs, all at least 12 weeks of age and weighing at least 2 kg (4.4 lb), were randomized in a ratio of 3:1 of fluralaner to positive control. Within households, one primary dog with at least 10 live fleas at enrollment was randomly selected. Flea counts were performed on all primary dogs every 4 weeks through week 12. Efficacy measurement was based on reduction from baseline flea counts. Treatment was considered effective if geometric mean live flea count reductions at weeks 4, 8, and 12 were 90% or greater and significantly different from counts at enrollment. In addition, for each time point the arithmetic mean live flea counts, the efficacy based on arithmetic means, the number and percentage of dogs with at least a 90% reduction in flea count, and the number and percentage of flea free dogs were calculated. Statistical comparisons were also made between treatment groups. RESULTS: At 12 sites, across 10 states, 121 households (221 dogs) were randomized to receive fluralaner and 44 households (100 dogs) were randomized to receive the positive control. Fluralaner was demonstrated to be significantly effective (all P ≤ 0.0001) at 4 weeks (99.8% reduction), 8 weeks (99.9%), and 12 weeks (99.9%). The positive control was significantly different from baseline (all P ≤ 0.0001) and showed a reduction of 81.2% at 4 weeks and was effective at 8 weeks (90.3%) and 12 weeks (93.0%). Arithmetic mean flea count reductions for the fluralaner group at 4, 8, and 12 weeks were 99.8, 99.9, and 99.9%, respectively. For the positive control, arithmetic mean flea count reductions were 58.8, 75.3, and 80.8% at 4, 8, and 12 weeks, respectively. No treatment-related serious adverse events were reported in either group. CONCLUSIONS: Owner-applied topical fluralaner treatment was safe in dogs and provided ≥ 99.8% flea control efficacy for 12 weeks.