Activity of a deltamethrin shampoo against Ctenocephalides felis and Rhipicephalus sanguineus in dogs

A controlled clinical trial was undertaken to assess the efficacy of an application of a 0.07% deltamethrin shampoo against fleas and ticks in dogs. Twenty beagles, housed in separate cages, were randomly allocated into two groups of 10. The dogs were infested with 50 Ctenocephalides felis and 50 Rhipicephalus sanguineus each, and parasites were counted 24 h (fleas) and 72 h (ticks) later (Day 0). Dogs, when state, were then treated with 25 ml of a shampoo containing 0.07% deltamethrin (Group 1). Dogs in Group 2 were the controls. Fleas and ticks were counted 24 h (Day 1) and 48 h (Day 2) after the shampoo was applied, and the parasites were then removed. All the dogs were reinfested with fleas and ticks on Days 2, 7, 9, 14, 16 and 20. Parasites were counted 24 and 48 h after each reinfestation. Effectiveness against fleas was calculated 24 h after infestation, and against ticks 48 h after infestation. This study showed that the application of 25 ml of shampoo containing 0.07% deltamethrin to beagle dogs weighing between 10.2 and 12 kg was very well tolerated. It controlled the parasites present on the animals at the time of application: with an efficacy of 100% against fleas 24 h after treatment and an efficacy of 95% against ticks 48 h after treatment. The treatment protected against flea reinfestations with an efficacy of 100% during the first week, >98% in the second week and >95% in the third week. It also gave >99% protection against tick reinfestations in the first week and >96% in the second week.