Dogs prone to allergies may develop problems with a number of things—all the way from food to inhaled pollens to flea bites. According to VCA Animal Hospitals, flea allergy dermatitis (FAD) is a condition that is especially prevalent during the summer months (or year round in warm climates) and is one of the most common dog allergies.
Many dogs exhibiting the signs of FAD do not have any visible fleas. VCA reports that the skin irritation and signs of FAD can occur from one single flea bite—resulting in days of itching for an affected dog. During feeding, the flea injects a small amount of saliva into the skin. Proteins in the saliva are what affected dogs are allergic to and causes the intense itching.
The most common clinical signs of FAD include itching and hair loss from the middle of the back to the tail base and down the rear legs, known as "the flea triangle." If an owner notices this pattern, he or she should bring the dog to a veterinarian health clinic for testing and to help reduce the pain and itching associated with the condition. VCA reports that a vet will usually suspect FAD if fleas are present or the classic clinical signs are visible. Other specialized tests such as intradermal allergy tests (skin tests) or specialized blood tests may also be used to confirm a flea allergy.
The most important part of treatment is strict flea control—both on the dog and in the environment. Flea medications—which prevent the parasites from biting the dog in the future—will be used and recommendations for treating the house and yard for fleas will be made. Additionally, many dogs require antibiotics to control secondary skin infections and anti-inflammatories to stop the severe itching. Some severely affected dogs may benefit from desensitization shot—also called allergy shots—in the control of their FAD.