Efficacy and Speed of Kill of a Combination of Fipronil/(S)-Methoprene/Pyriproxyfen Against Ctenocephalides felis Flea Infestations on Dogs from Day 2 to Day 30 Post-Treatment, Compared with a Combination of Fipronil/(S)-Methoprene

摘要

Three studies were performed to assess the efficacy, speed of kill, and residual effects of FRONTLINE (R) Gold for Dogs (fipronil/(S)-methoprene/pyriproxyfen, Boehringer Ingelheim, Merial, Inc., Duluth, GA) against Ctenocephalides felis fleas. Although temporally separate, all three studies were performed at the same facility, each using eight dogs per treatment group, with two treatment groups in the first two studies and three treatment groups in the third study. In the first study, 16 dogs were infested with 100 unfed adult fleas on Day 2 following treatment, and the fleas were removed and counted 30 minutes later. In the second study, the same dogs were infested with 100 unfed adult fleas on Days 2, 9, 16, 23, and 30 following treatment, and the fleas were removed and counted 12 hours later. In the third study, a group of eight FRONTLINE Plus-treated dogs were included, so 24 total dogs were infested with 100 unfed adult fleas, and the fleas were removed and counted 6 hours later on Days 2, 9, 16, 23, and 30. In the first study, dogs treated with FRONTLINE Gold had significantly (p=0.01) fewer live fleas than the control dogs 30 minutes post-infestation on Day 2. Geometric mean efficacy was 64.8%. In the second study, dogs treated with FRONTLINE Gold had significantly (p&0.01) fewer live fleas than the control dogs 12 hours post-infestation on Days 2, 9, 16, 23, and 30. Geometric mean efficacy was 100% on Days 2, 9, 16, and 23, and 99.1% on Day 30. In the third study, dogs treated with FRONTLINE Plus had significantly (p&0.01) fewer live fleas than the control dogs at 6 hours post-infestation on all assessments through Day 23, and significantly (p&0.05) fewer live fleas than the control dogs at six hours post-infestation on Day 30. FRONTLINE Plus Geometric mean efficacy was 99.3%, 100%, 99.0%, 97.4%, and 74.4% on Days 2, 9, 16, 23, and 30, respectively. Dogs treated with FRONTLINE Gold had significantly (p&0.01) fewer live fleas than the control dogs at six hours post-infestation on all assessments through Day 30. Geometric mean efficacy was 100%, 100%, 99.5%, 99.9%, and 98.4% on Days 2, 9, 16, 23, and 30, respectively. In this study, dogs treated with FRONTLINE Gold had significantly (p&0.01) fewer live fleas than those treated with FRONTLINE Plus on Days 23 and 30. A single dose of FRONTLINE Gold for Dogs (1.34 ml) demonstrated excellent efficacy, speed of kill, and residual effects against Ctenocephalides felis fleas for a full 30 days, and demonstrated better persistent speed of kill and residual effects than FRONTLINE Plus at the six-hour count for a full 30 days.