Effect of combing time on cat flea (Ctenocephalides felis) recovery from dogs.

Combing the haircoat to count fleas has been used to determine the efficacy of insecticides against fleas on dogs, but no standardization of method has been reported. In this study, the effect of combing time on flea recovery from dogs was examined. Six beagle dogs were infested with 100 unfed, adult Ctenocephalides felis (Bouché) on each of three consecutive days. A crossover design, balanced for carryover effects, was used to evaluate flea removal rates from each dog by comb-counting for three different time intervals; i.e. 5, 10 and 15 min. Each dog was combed once at each time interval on a different day, over three consecutive days. The results showed that the majority of fleas were recovered in the first 5 min of combing and there were no significant differences (P > or = 0.19) in the total number of fleas recovered between the 5, 10 or 15 min protocols. Moreover, the standard deviation and coefficient of variation increased with an increase in the amount of time spent combing, resulting in a decrease in precision for the longer protocols. Therefore, the comb time of 5 min provided a precise and accurate representation of the number of fleas present on an animal and could be useful as a standard measure of flea infestation levels in efficacy trials.