atopy in dogs

Atopy (Allergies) in Dogs

Overview of Dogs with Allergies

Atopy is a pruritic (itchy) skin disease of dogs that is caused by an allergy to substances in the environment that are contacted 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

Diagnosis of Canine Atopy

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

Treatment of Canine Atopy

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 for your dogs:

Home Care

Preventive Care

Atopy probably is an inherited disorder in dogs. Since environmental 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 dog’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.

Information In-Depth on Atopy in Dogs

Many skin diseases of dogs feature pruritus (itching) as a symptom and may appear similar to atopy. Ruling out other causes of pruritus is an important part of establishing a diagnosis.

Diseases that can appear similar to atopy include:

Diagnosis In-Depth

Veterinary care should include diagnostic tests and subsequent treatment recommendations.
Diagnostic tests are necessary to rule out other skin diseases, as well as to support the diagnosis of atopy. These tests may include:

Your veterinarian will get a complete medical history of your dog. Expect to be asked about the age of onset, whether the problem is or was at one time seasonal and where your dog chews and scratches. Bring a record of which medications your pet has previously been taking and be prepared to answer questions about how effective they have been.

Once the above diseases have been ruled out, a presumptive diagnosis of atopy is made. Allergy testing is then performed to identify allergens to which your pet is sensitive. Intradermal allergy testing (skin testing) is done to determine which allergens will cause a reaction. The hair is clipped from one side of the thorax and small amounts of many individual allergens are injected into the skin. Light sedation may be necessary to allow proper restraint during the procedure. This test usually requires referral to a veterinary dermatologist, which may necessitate travel to the nearest specialty practice. Your pet must be off all medications prior to testing so that the skin will react. Reactions to allergens in cat skin are subtler and therefore, are more difficult to read.

There is a blood test available for dogs to test for allergens by measuring the levels of IgE antibody to different allergens that are present in the bloodstream. IgE is the type of antibody that is involved in the allergic response. The advantage of this test is the convenience for the pet owner and the veterinarian. A blood sample is sent to one of several commercial laboratories. There is no need to travel to a dermatologist or to withdraw medications. However, false positive results are often a problem and this test is considered less reliable than skin testing. More accurate blood tests are being developed and this technique may be more viable in the future.

Treatment In-Depth

Two primary forms of treatment for atopy are available: drug treatment and immunotherapy. The ideal treatment for most moderately and severely affected dogs is some combination of both types of treatment. Drug therapy relieves the symptoms of atopy but does nothing to treat the underlying allergy itself. Most dogs with atopy are young and may require years of therapy.

Treatments for canine atopy may include one or more of the following:

Atopy is a disease that varies considerably in intensity depending on the individual animal and his present environment. Therefore, home monitoring and communication with your veterinarian is vital for success. Treatment is most likely to be effective if individualized to the dog.

Follow-up Care for Dogs with Allergies

Follow-up for canine atopy may include the following: