Skin Allergies, called allergic dermatitis, are the most common type of allergic reactions in dogs. There are three main causes of skin allergies in dogs:
- Flea allergy dermatitis
- Food allergies
- Environmental allergens
Flea allergy dermatitis is an allergic reaction to flea bites. Some dogs are allergic to flea saliva. This makes affected dogs extremely itchy, especially at the base of the tail, and their skin may become red, inflamed, and scabbed. You may also notice signs of fleas, such as flea dirt, or even see the fleas themselves.
Food allergies and sensitivities can cause itchy skin, as well. The most common places dogs with food allergies itch are their ears and their paws, and this may be accompanied by gastrointestinal symptoms.
Environmental allergens, such as dust, pollen, and mold, can cause an atopic allergic reactions or atopic dermatitis. In most cases, these allergies are seasonal, so you may only notice your dog itching during certain times of the year. As with food allergies, the most commonly affected areas are the paws and ears (but also include the wrists, ankles, muzzle, underarms, groin, around the eyes, and in between the toes.
All skin allergies pose the risk of secondary infection. As your dog scratches, bites, and licks at his skin, he risks opening up his skin to yeast and bacterial infections that may require treatment.