The affects of fleas on your pet dog can range from slight irritation and discomfort from the biting, to severe blood loss and anemia in extreme cases.

Your dog's excessive scratching due to fleas may be the result of an allergy your pet may have to the flea's saliva. Flea-Allergy Dermatitis is a severe reaction that can cause a pet to scratch or chew on their skin incessantly creating further irritation and the development of hot spots.

Besides external discomforts, fleas often are carriers of parasitic tapeworms. If a flea carrier is ingested, the tapeworm egg from teh flea will mature and attach itself to the intestinal lining of your animal and absorb nutrients passing your dogs intestinal tract.