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Lice Infestation

Lice are insects that can be seen with the naked eye. They are flattened and possess no wings. They are very host-specific and do not tend to leave their preferred animal, in this case dogs and puppies. Lice spend their entire life cycle on the pet. There are several kinds of lice. Blood-sucking lice belong to the group Anoplura. Those that do not suck blood, but rather chew skin, are grouped as Mallophaga.

Transmission of lice is by direct contact with an infested pet. Unlike fleas and ticks, lice do not persist or travel in the environment. Grooming instruments may, however, serve as a source of transmission.

Lice lay eggs (termed nits) on the hair shafts. The life cycle takes about 21 days to complete.

Trichodectes canis is the biting louse of dogs. Another commonly found biting louse of the canine is Heterodoxus spiniger. The only sucking louse of the dog is Linognathus setosus. Cats have one biting louse and that is Felicola subrostratus. None of these lice present a problem to humans.

The most noted sign of a louse infestation is a scruffy, dry hair coat. Hair loss may occur and the animal may itch, at times severely. In very heavy infestations of blood-sucking lice (biting), one may detect anemia, especially in puppies. A diagnosis can usually be accomplished with the naked eye. Nits tend to be more visible than the actual louse, but both can be seen.

Treatment is very simple. Both biting and chewing lice are easily killed with flea and tick products. We prefer to bathe weekly with a pyrethrin shampoo. Once the pet is dry, powder heavily with a flea and tick powder. Repeat this process weekly for four weeks. It usually is not necessary to treat the environment, but flea and tick foggers may help, especially in severe cases. Keep all grooming utensils clean.

Of all the parasites of dogs and cats, lice are the easiest to eliminate, and they pose no threat to you or your children.