A friend has adopted someones dog as the family are having a crisis. They family claim the dog had regular flea treatments, but its covered in flea poo, with several dead fleas and a few alive ones in the fur. I'd personally take it to a vet, but is there a way to remove flea poo? Does it just need a thorough wash with a medicated shampoo, or is there a fine, nit type brush she could use?