Fleas can occur year round in warm climates or on any pet that lives indoors. Adult fleas survive by feeding on blood. The preferred host for this meal is your dog and cat, but in heavy infestations, fleas will readily bite humans. Most dogs and cats that are bitten by fleas will have some itching, but some pets develop a severe allergic skin condition called flea allergy dermatitis. Heavy flea infestations can cause severe anemia and even death.
Fleas also carry dog and cat tapeworms.
These are passed to your pet when they ingest infected fleas. Fleas can be diagnosed on your pet by finding the adult fleas, the flea dirt, or flea eggs on the skin. These can be seen most easily on the rump and the thinly-haired belly. Flea dirt is actually flea feces from digested blood. It looks black, but will appear red brown when smeared on a white paper.