Poor Gracie, a 2-year old West Highland White Terrier, was itching all over. Some nights she stayed awake almost all night scratching at her skin and ears, and her formerly snow-white feet were beginning to stain a reddish-brown color from constantly being licked and chewed. She didn’t have fleas or any apparent skin infection, and baths with oatmeal shampoo weren’t helping. Gracie was miserable, and her mom had no idea what was wrong.
After a trip to the veterinarian, who was able to rule out parasites, bacterial infection, and yeast, Gracie finally got her mystery illness diagnosis: Atopy.
What Is Atopy?
Atopy, also referred to as atopic dermatitis, is a common condition in dogs and cats. It’s a skin disease caused by an allergic reaction to something in the environment (called an allergen) that’s either inhaled or comes into direct contact with the skin. Although we humans typically experience respiratory symptoms (such as sneezing or a runny nose) with our inhalant allergies, pets tend to display their allergic reactions through their skin and hair coat.
Atopy is the second most common type of allergy in dogs and cats, just behind flea allergy dermatitis. It affects approximately 10 to 15 percent of dogs, with a percentage just slightly lower for cats. In dogs, atopy usually shows up between the ages of 1 and 3 years, while atopy in cats can occur at any age. In both dogs and cats, symptoms often get worse with age.
A tell-tale sign of atopy is that it tends to be seasonal, and its severity can increase and decrease depending on the time of year. However, pets who are allergic to indoor allergens (such as dust mites) can have problems year-round.
Common Atopy Triggers
Allergens that most commonly cause atopy symptoms include:
- Tree pollens
- Grasses and grass pollen
- Weed pollens, such as ragweed
- Dust mites
- Chemicals found in rubber or plastic materials
- Certain fabrics, such as wool or nylon
Unfortunately, most pets with atopy are allergic to more than one thing. Once these allergens are inhaled or come into contact with skin, they cause the immune system to overreact and produce a protein called IgE. This protein sticks to specialized cells in the skin called mast cells, and causes them to release the chemical histamine. It’s histamine that actually causes the intense itching associated with allergic reactions and atopy.
Are Certain Breeds More Likely To Be Affected?
Although any dog or cat (including mixed breeds) can suffer from atopy, there seems to be a strong genetic component for atopy in certain types of dogs. Susceptible breeds include:
- Boston Terrier
- Cairn Terrier
- English Bulldog
- English Setter
- Golden Retriever
- Irish Setter
- Labrador Retriever
- Miniature Poodle
- Miniature Schnauzer
- Scottish Terrier
- Sealyham Terrier
- Shih tzu
- Tibetan Terrier
- West Highland White Terrier
- Wire-haired Fox Terrier
In cats, there don’t seem to be any specific breeds that are more affected than others.
Symptoms Of Atopy
At first, atopy symptoms may be mild, but they tend to get progressively worse.
Symptoms in dogs include:
- Intense itching, which causes scratching, licking or biting of the feet and belly, and rubbing of the face
- Skin redness
- Patchy hair loss
- Skin thickening
- Darkening of skin color in certain areas
- An unusual odor to the skin
- Scratches, skin infections, or open sores
- Greasy, flaky, crusty, or scaly skin
- A red or brown tint to the fur where the dog has been licking or chewing, especially around the legs and feet
- Recurring ear infections, or red, irritated ear flaps
- Sneezing, runny eyes (these are not as common as skin symptoms)
Symptoms in cats include:
- Pulling out tufts of hair; patches of hair loss in equal patterns on the fur
- Red, irritated, or itchy skin
- “Twitchy” skin
- Long, thin, red lesions, or crusty bumps with bloody scabs, on the skin
- Open, oozing sores
For both dogs and cats, affected areas are often found on the feet, face, abdomen, ears, armpits, groin, and at the base of the tail.
Atopy is usually diagnosed only after all other potential causes of itchiness (including mange, flea bites, food allergies, and other skin disorders) have been ruled out. Allergy testing can identify which allergens your pet is allergic to, but is usually only recommended if you’re planning to begin immunotherapy (allergy shots) for your pet.
If you plan to give allergy shots, a veterinary dermatologist can perform intradermal skin testing. This is the allergy “skin test” similar to the one performed on people, and it remains the most accurate way to diagnose allergies. In intradermal testing, the veterinarian injects a tiny amount of an allergen into a pet’s skin. If the body responds to the allergen, the pet is considered allergic to that substance.
There is another more recently developed test available called IgE Allergy Testing. This is a blood test that checks for the presence of antibodies against specific allergens. If you decide to pursue allergy testing, your veterinarian will discuss both testing options with you to determine which one is best for your pet.
Treatment Options For Atopy
There are 4 common treatment options typically used for atopic pets:
- Removing allergens from the environment.
This includes known or suspected allergens, such as fleas, ticks, dust and dust mites, pollens, household cleaners, or other skin irritants. Some dogs also benefit from switching to a hypoallergenic diet, even if they don’t have food allergies. This is because dogs who are allergic to dust mites can also have cross-reactions to grain mites, so they tend to do better on food that doesn’t contain grains.
- Treating symptoms with specific medications.
The most common method of treating atopy is to treat symptoms directly through the use of antihistamines, prescribed medicated shampoos, fatty acid supplements (which reduce skin inflammation), anti-itch ointments (those containing the topical anesthetic Pramoxine work particularly well), and antibiotics to treat secondary infections in the skin.
Immunotherapy is started once a pet has been allergy-tested and the specific allergens causing the problem are identified. A serum containing tiny amounts of these allergens is created specifically for the pet, and is injected under the skin on a regular schedule determined by the veterinarian.
The goal of immunotherapy is to slowly desensitize a pet’s immune system to the allergens he is reacting to. This process can take up to 12 months (longer in some cases), but many dogs and cats experience a dramatic reduction in symptoms with immunotherapy.
- Suppressing the immune system response with corticosteroids.
If a pet does not respond to the treatments mentioned above, as a last resort, corticosteroids (such as prednisone, hydrocortisone, or dexamethasone) or the immune-suppressing drug cyclosporine can be used to reduce the body’s severe reaction to allergens.
Steroids, although extremely effective at reducing symptoms of atopy, must be used very carefully. They can have numerous side effects if used long-term, including liver problems, diabetes, and problems with the adrenal glands.
Can Atopy Be Prevented?
The short answer is, not completely. However, steps can be taken to reduce the likelihood of your dog or cat experiencing allergy flare-ups that can lead to atopy.
- Keep windows closed and use air conditioning instead.
- Vacuum and dust often to reduce dust in the environment. However, keep pets out of the room for several hours after vacuuming and dusting, if possible!
- Keep your pets indoors during peak allergy season when pollen counts are high.
- Change furnace and air filters regularly.
- Keep pets out of the basement to reduce exposure to mold or mildew.
- Wash bedding frequently in very hot water to kill dust mites.
- Keep pets indoors when the lawn is mowed or trees are trimmed.
- Avoid having large numbers of houseplants in your home.
- Wipe pets down with a damp towel after they’ve been outside to reduce the amount of pollen stuck to their fur.
Many veterinarians agree that because the tendency to develop atopy seems to be genetically inherited, the only true way to prevent it in future generations is to not use animals with atopic dermatitis for breeding.
Long-Term Management of Atopy
Atopy is one of the most frustrating skin disorders, both for pets and their guardians. Although it isn’t a life-threatening condition, atopy can cause a great deal of misery for poor dog or cat who suffers from it! Management of this condition requires regular veterinary care and diligence on the part of the pet parent to make sure that atopic pets maintain a good quality of life.
Although atopy can’t truly be “cured”, with patience, dedication, and an investment of time, it can usually be successfully managed with lifestyle changes, a hypoallergenic diet, and medication. For those pets on long-term medication, visits to the veterinarian twice a year are important for successful management of atopy.
Have you ever treated your dog or cat for atopy? If so, what treatment options worked best for you? Please share your story with us in the comments below!