Have you discovered any ant-like animal - but that doesn't jump - on your dog? They are, most probably, dog lice. When there are many, lice can do a lot of harm to the, as they cause anemia.Lice only live on whereas fleas can temporarily jump onto humans. In case of a lice infestation, an insecticide bath is recommended, which will be repeated as many times as you veterinarian indicates you to do so, as their eggs, stuck to the hair, are not easily removed by most products on the market. Luckily though, lice are not common nowadays amongst well-cared .
Suggestion: You can ask your veterinarian to give you a preparation which acts internally. The dog will then, so to speak, remain impregnated and, when the louse bites, it will absorb a mortal toxic substance. That way your dog´s torturers will, slowly but surely, go dying.