Dogs serve as hosts to a number of parasites. You will probably be asked to bring a fecal sample to your dog’s yearly vet appointment, so that the staff can check for the presence of internal parasites. If you notice small, rice-like granules on your pet’s bedding or around her anus, she is suffering from an infestation of worms and needs to be seen by your vet to get proper treatment.Other parasites take up residence on the outside of your dog’s body. Mange and sarcoptic mites live on the hair follicles and skin of dogs, while ear mites live on the inside of the ear. These parasites are so small you might not see them, but they cause your dog extreme discomfort. Head shaking and pawing at ears are signs of ear mites. Frequent scratching and skin-biting can indicate either skin mites or a dog’s worst enemy-fleas.