Dealing with Dog Allergies

Your doggie scratches and scratches and scratches. His paws are red and his skin is irritated. You check for fleas; you give him oatmeal baths; but nothing seems to help. Your itchy pet may be suffering from atopy.

Atopy is a pruritic (itchy) skin disease of animals caused by an allergy to substances in the environment. The substances are contracted through the air, either by absorption through the respiratory tract or contact through the skin. Atopy is thought to be an inherited disease. It is the second most common allergic skin condition in dogs; only flea allergy dermatitis is more common.

Symptoms of atopy usually begin relatively early in life, often by one year of age. Symptoms usually are seasonal at first, with most dogs showing clinical signs in the summer months when airborne allergens (such as plant pollens) are present in higher concentrations. As atopic dogs age, their symptoms tend to become less seasonal as they become allergic to more substances. Eventually, their itchiness can occur year-round.

Dogs with atopy are usually itchy, particularly the hands and feet. The skin may be red and irritated due to scratching, and the ears may also be inflamed. The symptoms of food allergy are difficult to distinguish from those of atopy.

What to Watch For

Signs of atopy in dogs may include: 

Chewing at the paws

Scratching the muzzle or rubbing it on the ground or with the paws

Scratching the ears

Shaking the head

Diagnosis of Atopy in Dogs

Diagnostic tests are necessary to rule out other skin diseases, as well as to support the diagnosis of atopy. These tests may include:

A complete medical history and a thorough physical examination, especially checking the ears and the skin of the face and paws. Often, abnormalities may not be detected on the physical examination of dogs with atopy. Occasionally, redness between the toes or around the muzzle of the face is the only finding.

Skin scrapings to eliminate other diagnoses such as demodectic or sarcoptic mange (caused by mites).

Fungal culture to rule out ringworm (also called dermatophytosis).

Skin testing (or occasionally blood testing) to determine specific allergens to which your pet may be allergic.

Treatment of Atopy in Dogs

Initial treatments may alleviate symptoms, but do not treat the underlying cause of the allergy. Immunotherapy (allergy shots that work by modifying your dog’s immune response to allergens) is considered the best treatment for moderate to severe or long-standing cases of atopy.

Your veterinarian may recommend the following:

Antihistamines

Fatty acid supplements

Antibiotics to treat secondary bacterial infection of the skin (called pyoderma)

Soothing shampoos

Corticosteroids (cortisone-like drugs such as prednisone) are very effective at reducing the symptoms of atopy, but they have many potential side effects that limit their long-term use. Corticosteroids should be used cautiously in the treatment of dogs with atopy.

Cyclosporine ( Atopica®, Novartis)

A newer therapy called Oclacitinib (Apoquel) has been very effective in control of itching in dogs with allergies.

Home Care

Atopy cannot be cured and most dogs require some form of therapy throughout their lives. You will need to administer any medications prescribed by your veterinarian and avoid offending allergens as much as possible. Skin testing (also called allergy testing) can be performed to identify the specific substances to which your dog is allergic. As time goes by, however, most dogs with atopy become allergic to more and more allergens, making avoidance impractical in the long run.

You should practice strict flea control. Other itchy (pruritic) skin diseases such as flea allergy dermatitis may have an additive effect on your dog’s skin condition.

Observe your dog for rashes and worsening of any skin lesions. Secondary bacterial infection of the skin (pyoderma) is common in dogs with atopy and can contribute to their discomfort.

Preventive Care

Atopy probably is an inherited disorder in dogs. Since enviromental exposure to allergens is important in the development of disease, it cannot be prevented. Airborne allergens, such as plant pollens, are difficult to avoid, and there is little that can be done to prevent the development of atopy in a predisposed individual. Dogs that grow up in low allergen environments (dry climate with high elevation) may be less likely to develop symptoms.

Managing atopy in your dog takes some patience. However, by combining different methods of therapy, paying attention to your pet’s environment as well as you can, and observing your pet so that you can begin treatment as early as possible, you can make your pet feel his best.