Perhaps you’ve noticed lately that your dog has a new favorite hobby — scratching himself in three places at once. When you finally get close enough to examine the problem, you part his coat and find tiny white particles resembling dust. You try to brush them away, but they’re stuck to the hair shafts. What are these tiny white things, and why do they make your dog itch?

Your dog has been infested by lice. Dog lice aren’t the same kind of parasite as human lice, but they’re just as miserable for your dog. Six-legged creatures that actually chew your dog’s skin, dog lice trigger severe itching and after a certain point, hair loss. The white particles you see attached to his hair, close to the skin, are eggs and nits. Both are visible to the naked eye.

It’s not common for dogs to get dog lice — unlike fleas or ticks, many owners never have to deal with this particular shady character. It’s much more common for humans to get human lice. But dog lice still exist, and dog still pick them up, especially from group environments like kennels or shelters.

One little louse can’t do much damage to your dog, but once that louse propagates, your pet can literally be eaten alive. In very serious, untreated cases of dog lice, dogs have been known to lose up to a quarter of their blood volume within months. In this severe form of infestation, the dog begins to suffer from anemia and shock.

Learn more about dog lice.