Main facts about lice
Lice affecting pets are insects and can be divided into two categories: sucking lice (Anoplura), hematophagous (blood-sucking) parasites related to human lice, or chewing lice (Mallophaga). The main lice in dogs are Linognathus setosus (sucking lice) and Trichodectes canis (chewing lice) and in cats are Felicola subrostratus (chewing lice).
Even though they are extremely small, both lice and their eggs can be seen with the naked eye.