Comparative Efficacy of fipronil/(S)-methoprene-pyriproxyfen (FRONTLINE® Gold) and Sarolaner (Simparica®) Against Induced Infestations of Ixodes scapularis on Dogs.

A study was performed to compare the 12-hour efficacy of FRONTLINE® Gold (fipronil/(S)-methoprene/pyriproxyfen) with that of SIMPARICA® (sarolaner) against Ixodes scapularis tick infestations on dogs. Based on pre-treatment tick count, 24 dogs were allocated to one of three groups, eight dogs in each group. On Day 0, each dog in Group B was treated with a dose of commercially available FRONTLINE Gold for Dogs appropriate for its weight, and each dog in Group C was treated with a dose of commercially available SIMPARICA appropriate for its weight. Group A dogs remained untreated throughout the duration of the study. On each of Days 1, 7, 14, 21, and 28, all dogs were infested with 50 live, unfed Ixodes scapularis ticks, and at 12 hours post-infestation on Days 2, 8, 15, 22, and 29, ticks were removed from all dogs and counted. Using arithmetic means for all calculations, dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live ticks than the controls at 12 hours post-infestation on all evaluation days from Day 2 to Day 29. FRONTLINE Gold 12-hour arithmetic mean efficacy was 99.1%, 100%, 100%, 100%, and 94.7% on the same days. Dogs treated with SIMPARICA had significantly (p<0.01) fewer live ticks than the controls at 12 hours post-infestation on the same days. SIMPARICA 12-hour arithmetic mean efficacy was 97.0%, 96.1%, 92.6%, 87.3%, and 84.5% on the same days, respectively. Dogs treated with FRONTLINE Gold had significantly (p<0.05) fewer live ticks than dogs treated with SIMPARICA on Day 15. [ABSTRACT FROM AUTHOR]