Canine Biting Louse (Trichodectes canis)

In the wingless insect suborder of chewing lice (Mallophaga), Trichodectes canis is the louse species that most commonly feeds on domestic dogs and other canids such as coyotes, wolves, and foxes, which may come into contact with dogs. Unlike ticks and other parasites, the 2,800 species of biting lice described worldwide are very host-specific. The dog louse, or canine biting louse, is about 1.5 millimeters in length with a dorsoventrally flattened body and a broad, flat head. As representatives of the Isonocera group, chewing lice extend their highly visible trisegmented antennae laterally. Each of the six legs (three pairs) is armed with a strong claw for holding onto the host canid, even in the face of frantic biting and scratching.