Lice are dorsoventrally flattened wingless insects (i.e., with three leg pairs and a distinct head) and are small (about the same size as fleas).
Trichodectes canis is a chewing louse found on dogs and wild canids throughout the world and is a vector of the dog tapeworm, Dipylidium caninum.
Linognathus setosus is a sucking louse occasionally found on dogs (particularly on long-haired breeds) throughout the world.
Lice spread between hosts usually through direct contact from dog to dog, but transmission can also occur via eggs on fomites such as brushes, combs, or similar grooming equipment.
The active ingredient, Fipronil is a well-known insecticide and effective against lice. Following application of Effitix to the skin, fipronil dissolves in the skin’s oily sebaceous layer and spreads across the skin surface. Fipronil is concentrated in the sebaceous gland, the epithelial layers surrounding the hairs, and the exposed part of the hair shaft after treatment, where lice may be present.
The active ingredient permethrin is a fast-acting adulticide and repellant of lice. Effitix has rapid knockdown and repellency. This rapid killing in addition to prevention of attachment can be important to reduce your dog’s chances of pathogenesis of vector-borne diseased. After application of Effitix, the pyrethroids bind tightly to the hair shaft when they reach the hair follicle and persist there, thus blocking lice. The compound exerts a toxic effect on the nerves of the parasite, acting as a noxious stimulus.