Trichodectes canis: Canine biting louse

Linognathus setosus: Canine sucking louse

General Description: The canine lice are about 1.5mm long, with bodies flattened top to bottom. The biting louse (Trichodectes) has a broad, round head, whereas the sucking louse (Linognathus) has a short blunt head.

Life Cycle: The life cycle takes 3 to 4 weeks and is characterised by incomplete metamorphosis, as described in the Overview.

Location: Anywhere on the body.

Geographical Distribution: Most countries.

Significance: While not common on healthy animals, heavy infestations can occur on poorly nourished dogs, adding to their debilitation.

Effect on Host: Lice cause severe itching. Infested dogs continually scratch, may damage their skin and coats, and do not sleep well. In addition, the sucking louse feeds on blood, and in heavy infestations can cause anaemia and loss of condition. Trichodectes canis can serve as the intermediate host for the dog tapeworm, Dipylidium caninum.

Diagnostic Information: Identification of adult lice on the skin.

Control: The entire louse life cycle is spent on the hosts, so louse control primarily involves treating infested dogs with insecticides in the form of dips, sprays or shampoos. Adequate nutrition makes animals less susceptible to lice. FRONTLINE® kills biting lice.

Adult biting louse		Louse egg "nit"		Pediculosis (L.setosus)