PATHOLOGY

Detailed explanation-1: -Flea allergy dermatitis (FAD) is a leading cause of allergic reactions in dogs. In an allergic reaction, the body’s immune system overreacts or is hypersensitive to a substance (antigen) that is usually harmless. “The antigens in the saliva cause an intensely itchy response in sensitive dogs."

Detailed explanation-2: -FAD also known as flea bite hypersensitivity is an allergic reaction to flea saliva injected by the bites of fleas. Clinical signs can be either a seasonal problem or can be year-round depending on environmental conditions (BOX 1).

Detailed explanation-3: -Flea saliva can cause an inflammatory reaction in animals that are sensitive to it. Some dogs have an immediate hypersensitivity to it within 15 minutes, while others have a delayed reaction that takes 24-48 hours. Dogs with atopic dermatitis are more likely predisposed to developing flea allergy dermatitis (FAD).

Detailed explanation-4: -Summary. Flea allergy dermatitis (FAD) is a skin condition of dogs and cats that’s caused by an allergic reaction to flea saliva. An allergic reaction to certain proteins in the flea’s saliva occurs after a flea bites and feeds on a pet’s skin.