Canine atopic dermatitis can also be known as allergic dermatitis, atopy, environmental dermatitis, hay fever, among other names.
What is atopic dermatitis?
Atopic dermatitis is one of the most common causes of chronic itching in dogs. Atopic dermatitis is caused by an allergic reaction (hypersensitivity) to one or more substances in the environment. Various substances, called allergens, can trigger atopic dermatitis. They are often the same allergens implicated in human allergic conditions such as hay fever and asthma. Florida is one of the climates where atopy is most prevalent. In Florida, we see atopy cases in almost every breed and age of dogs.
What are the symptoms of atopic dermatitis?
Dogs with atopic dermatitis are usually itchy. The face and feet may seem particularly irritated. The skin on some parts of the body may be reddened, moist, or damaged due to scratching or chewing. Skin infections may also occur. The ears may also be inflamed, and recurrent ear infections are quite common in these patients. Less often, dogs with atopic dermatitis have other signs of “allergies” including runny eyes or nose. The symptoms usually start when the dog is 1 to 5 years old and may worsen over the first couple of years if not treated. Unlike many humans, dogs do not “grow out” of their allergies – so we almost always recommend long-term treatment.
Why does atopic dermatitis develop?
A combination of factors predisposes dogs to atopic dermatitis. Both their genetic make-up and environment may interact to allow atopic dermatitis to develop. The condition is caused by an inappropriate immune reaction rather than by the allergens themselves.
How are dogs exposed to allergens?
Many allergens are airborne and found nearly everywhere. Some are present year-round (such as house dust, dust mites, and some molds) while others are found at high levels only at specific times during the year (such as pollens). Dogs may either inhale the allergens or contact them through the skin.
How is atopic dermatitis diagnosed?
The diagnosis is based on your observations and on our physical examination, as well as by ruling out other causes of allergies, primarily parasites (fleas and mites) and food.
Can we test my dog for allergies to find out what he/she is allergic to?
Allergy testing is useful in determining what allergens are specific to your pet, therefore we can formulate a plan to try and avoid the allergens. Allergy testing can be done via a blood sample (antibody test), and intradermal or a pinprick test. The former can be performed with your primary care veterinarian, and the latter two are performed with a veterinary dermatologist. One of Dr. Joi’s gifts to clients is offering allergy testing (the blood sample version mentioned above) AT COST. Most clinics charge several hundred dollars for this test, but we give it to you at $170. Pets should be at least 2 years old at the time of this blood test because it is an antibody test.
How is atopic dermatitis treated/managed?
Atopic dermatitis can be treated/managed in many ways. What works great for one dog may not help another dog. Limiting your pet’s exposure to his/her allergens is most effective, but not usually practical – it may mean relocating to a different climate! Other treatments are usually necessary. These include:
It is also very important for any dog with atopic dermatitis to be on a year-round, comprehensive flea control program. Atopic dogs tend to be more sensitive to the bites of fleas, so we would like even occasional fleabites to be prevented. The flea products that Dr. Joi, Dr. Javi, and Dr. Bill most often recommend are NexGard® or Bravecto®, but other options are available such as Revolution® if your pet has a severe food allergy. We also love Sentinel as our heartworm prevention because it has an ingredient to help break the flea life cycle, that we call flea birth control.
Anti-inflammatory and anti-itch treatments
Apoquel®, Atopica®, Cytopoint™, fatty acid supplements, prednisone, or other medications may be very helpful to reduce itching in your pet. Apoquel and Atopica are the only FDA-approved non-steroidal drugs for the management of canine atopic dermatitis. Apoquel (oclacitinib) blocks the receptor for IL-31, a molecule that signals itchiness in dogs. IL-31 can also be blocked with a monoclonal antibody, (Cytopoint™), given as a subcutaneous injection every 4-8 weeks. It can be truly amazing to provide chronically itchy dogs such as quick relief without using steroids. Since each atopic dog is very much an individual, some dogs need a “trial” with different drugs to find the one or combination that works best. There are no known side effects to Cytopoint™ and often times pets come in for an appointment for Cytopoint™ with one of our vet nurses.
Medicated shampoos, topical sprays, and mousses can provide relief to many dogs. Bathing removes the allergens that are adhering to the surface of the skin, and the medicated ingredients also help to reduce itching and control/treat secondary infections. We particularly prefer Malaseb™ shampoo as it has 7 days of residual activity.
Antibacterial and antifungal medications
Dogs with atopic dermatitis are prone to recurrent bacterial and yeast infections of the skin and ears, therefore we may need to address these infections in addition to treating atopic dermatitis. These might include oral antibiotics and antifungals alone but more often in combination with topical therapy with antibacterial and antifungal shampoos/sprays/mousse as mentioned above. Cleaning the ears on a regular basis and especially after the ears get wet with a medicated ear cleaner helps to reduce the risk of an ear infection.
This is the only treatment that can cure allergies. Beginning this treatment before the allergies are too severe increases the odds of a successful outcome. An extract made from allergens that your pet is sensitive to can be given to induce “tolerance” to these substances. When these substances are then encountered in the environment, your pet should be much less sensitive to them. Two routes of administration are available: subcutaneous injections or oral/sublingual. This form of treatment is performed with a veterinary dermatologist. We strongly prefer the sublingual route. Please note that the pet will be on the hypo-sensitization for years. 60-80% of atopic dogs respond to hypo-sensitization and it can take 8 to 12 months to take effect.
At times we may refer you and your pet to our local veterinary dermatologist for further care and testing.
Managing this lifelong condition takes some patience. By using various combinations of therapy, and altering the treatment based on the pet’s response, we can help atopic dogs feel and look their best!
Dr. Javiera Correa August, 2020