The most common symptoms of a lice infestation in dogs are excessive scratching, a scruffy-looking dry coat and hair loss. A visual check is the simplest way to confirm.
Adult dog lice are dark, flat insects with six legs and no wings. These insects are typically seen near the skin of your dog, latched onto the hair. Unlike dog fleas that lay eggs in the environment surrounding your pet, lice lay their eggs in your dog's coat. The eggs of lice are attached to individual hairs and appear as white dots in your dogs coat.
Depending upon the type of louse, it feeds on your dog in two different ways. One bites and chews the skin, the other simply sucks its blood. Both forms of feeding cause excessive itchiness and scratching, a symptom that can eventually lead to hair loss near the ears, neck and groin.