Ingestion of fleas while chewing or grooming leads to tapeworm infections. These are usually seen by the client as objects resembling grains of rice or sesame seeds under the tail. Medications are available to eliminate the tapeworms, but adequate flea prevention will also prevent tapeworm infestations.
If a pet is sensitive or allergic to anything, they are usually also allergic to flea bites. Clients often don’t see the fleas because the pet is grooming or chewing and removing them. When a pet brings fleas into the house, they will hop off and lay eggs in the area leading to an explosion in numbers.