All pets except those living at altitudes above 5000 feet can be affected. Fleas occur year-round in pets living indoors. Fleas survive by feeding on blood. In most dogs and cats, flea bites cause a mild itching but can cause a severe allergic skin condition called flea allergy dermatitis. A heavy flea infestation can cause more serious diseases such as anemia and even death.
Fleas are also the intermediate host of the dog tapeworm.
Fleas can be diagnosed by finding the actual fleas crawling around on the dog or cat or by seeing flea dirt on their coats. Flea dirt is flea feces and flea eggs that are found on the animal's coat and looks like black and white particles the size of sand grains. Flea feces is actually digested blood and can be distinguished from plain dirt by brushing some onto white paper. Flea feces will cause reddish brown streaks when rubbed against the paper. It's easiest to find fleas crawling around on your dog by turning your pet over on its back and carefully examining the thinly haired portion on the lower part of the abdomen.