Flea allergy dermatitis (FAD) is the most common skin condition in dogs. Dogs can develop this allergy as early as their first year, and it most commonly starts when dogs are young - up to five years old. Dogs of any age can develop FAD, though, and the symptoms of flea allergies will worsen with age.
Fleas are parasites that evolved to puncture the skin of dogs for their blood meal. Dogs typically react to flea bites with itching, redness, and inflammation. But dogs who are allergic to flea bites will have more severe symptoms and a much stronger, prolonged sense of itchiness.
Dogs who are hypersensitive to flea bites are reacting to antigens in the the flea’s saliva that their immune system does not recognize. Once bitten by a flea, the compounds in the flea saliva pass through the dog’s skin, causing a reaction that produces severe itching, redness, and swelling.
When an allergic dog is exposed to flea saliva, the area will become red, bumpy, and inflamed. With even one or two bites, the dog will feel constant itchiness and discomfort. And in severe cases, dogs will develop lesions and experience hair loss. Dogs who are allergic to flea bites often do more damage by scratching and biting the inflamed skin affected by the flea saliva. This creates an environment on the skin that is ripe for infection and secondary disease.
Flea allergy dermatitis cannot be cured, though desensitization therapy, like allergy shots, is an option. Removing fleas completely is the most effective way to protect your dog from flea bites, thus eliminating the cause of the skin condition. There are many ways to prevent fleas from infesting your pet, home, and yard, as well as treatments to relieve skin conditions associated with the allergy.
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.