Abstract
In three dogs infested by fleas and not satisfactory treated with a fipronil or an imidacloprid product, flea specimens were collected and identified as the cat flea Ctenocephalides felis. Drug-sensitivity of each isolate of the fleas was evaluated to permethrin, fipronil and imidacloprid by in vitro knockdown tests, and it was revealed that each isolate was very insensitive to the drug that had been used for the treatment. The fleas on the 3 dogs were then completely eliminated with a drug to which each flea isolate was sensitive at in vitro evaluations.
