Evaluation of the Ovicidal Activity of Lufenuron and Spinosad on Fleas' Eggs from Treated Dogs

摘要

This study was conducted to compare the production and viability of flea eggs on dogs treated with either the combination of milbemycin oxime-lufenuron or spinosad. Fifteen dogs were randomly distributed into three treatment groups and housed individually. Dogs in group 1 served as untreated controls, dogs in group 2 were treated with milbemycin oxime-lufenuron, and dogs in group 3 were treated with spinosad. Products were administered orally according to label directions on days 0, 30, and 60. All dogs were infested with 250 cat fleas, Ctenocephalides felis, KS1 strain, on days 14, 28, 42, 49, 58, 70, 77, and 88. Forty-eight hours after each infestation, dogs were placed into egg collection cages for 3 hours. Flea eggs were collected, counted, and placed into rearing media to determine adult flea emergence. The percent adult flea emergence from eggs collected from untreated control dogs ranged from 19.3% to 69.4% throughout the study. Eggs collected from dogs treated with spinosad had percent adult emergence of 49.2%, 20.3%, and 37.9% on collection days 30, 60, and 90, respectively. Even though eggs were collected on days 51, 72, and 79, those eggs were not viable. No adult fleas developed from eggs collected from dogs treated with lufenuron-milbemycin oxime over the entire 90-day study.