Just as airborne allergies are common in people, manifesting as itchy eyes, sneezing, and congestion, allergies are also common in dogs (and cats!). As the weather warms up and our furry friends spend more time in the spring sunshine, their exposure to outdoor allergens increases. Some inhalant allergies are prevalent year-round, such as those activated by house dust mites or food storage mites, but many airborne allergies are seen during particular times of the year. Atopy, another name for airborne allergies, is typically triggered by grasses, pollen, weeds, trees, dander, mold spores, insect proteins, and even fabric. Dogs living in different parts of the country may experience allergy symptoms during different months, all depending on the weather and what is blooming!
Signs & Symptoms of Allergies in Dogs
Pets with atopy usually experience a seasonal spring or fall itchiness that begins in the first or second year of life; often the duration of the itchy period becomes longer and longer. Other dogs start the itch-scratch cycle like clockwork on the same day every year and symptoms predictably last just a few weeks. Itch and skin redness, bacterial infection, scabbing, hair loss, licking or swelling is associated with certain parts of the body in atopic dogs. Hair loss around the eyes and mouth, in the dog’s “armpits” or axillary and inguinal regions, the lower abdomen, around the rear end, and feet are the first clues your dog may have airborne allergies. Ear infections are common secondary problems; the heat from inflamed skin make the dark canal a perfect environment for bacteria or yeast to overgrow.
I get countless calls where an owner has self-diagnosed ear mites because of a black, smelly ear discharge that causes intense itching. Yeast overgrowth, caused by underlying allergies, is a more common culprit. Without treating both the infection and the allergy, ear disease is likely to become chronic. While some dogs also experience red, itchy eyes and have more mucous production, we rarely see the nasal and sinus congestion that people suffer, though a few pets do develop an allergy-triggered bronchitis or a throat-clearing rumble.
What causes allergies in dogs and why do some react while others don’t?
An allergy is a state of over-reactivity or hypersensitivity of the immune system to a substance called an allergen. Chronic exposure to the offending protein allergen, sensitizes or prepares the immune system to react, in this case over-react, on subsequent exposures. Normally the immune response protects the dog against infection and disease by making protective antibodies, but with allergies, the immune response can be harmful to the body accumulating in a cascade of events leading to histamine release and itch. It is thought that there is a genetic component in dogs with atopy. Terriers, such as the West Highland White Terrier, Retrievers, Pugs, and Bulldogs are over-represented.
Treatment For Dogs With Allergies
As any veterinarian will tell you, atopy is a disease that we manage, not cure. As the immune system is the “problem”, most treatments are aimed at decreasing the body’s over-reaction and modifying the dog’s environment to reduce exposure to the offending allergen(s). As such, it is important to identify which proteins triggers your pet’s itch. The gold standard in allergy testing remains intradermal skin testing. This test is performed by a veterinary dermatologist and involves injecting small amounts of different allergens under your pet’s skin to evaluate the immune system response. Some veterinarians offer blood testing, which identifies allergens via antibody levels.
Once the allergens are identified, we attempt to limit environmental exposure as much as possible. HEPA filters, vacuuming, washing bedding, cutting back weeds and limiting time outdoors during allergy season can help. Frequent bathing and wiping your dog’s fur and feet with a medicated shampoo or wipe can minimize absorption of allergens, promote a healthy skin barrier, and soothe the itch. Fatty acids in liquid or capsule form act as anti-inflammatories and can reduce signs of dog allergies. Too much can be a bad thing and can cause problems with blood clotting and wound healing; a dose between 20-55mg combined EPA and DHA per pound of body weight is safe for dogs and cats.
Dog Allergy Medicine
Anti-histamines such as Benadryl and Atarax are effective for dog allergy medicine – only about 25% of our patients. Newer dog allergy medications such as Apoquel tablets and injectable Cytopoint have been life-savers for many dogs and their frustrated owners. Apoquel works by affecting messengers of the itch, called cytokines, and can stop symptoms in 4 hours. It is a daily pill and good for short-term itch flares-ups. Apoquel causes minimal interference with healthy immune system function and is preferred over corticosteroids or cyclosporine, the administration which can lead to endocrine disorders, immune-suppression, and increased urination. Cytopoint is a convenient injection that acts as an antibody to block the itch signal; it also begins working within hours and lasts 4-5 weeks.
Ultimately, to affect long term change, the goal is to desensitize the dog to the same allergens they currently react to. Dog Allergy “shots” or oral drops are formulated with increasing amounts of allergen and administered regularly to permit the immune system to recognize the allergen without going into a tailspin. About 2/3 of dogs get relief from desensitization therapy, but it is a financial and time commitment to follow-through with treatment on the part of the owner.
With so many options available to manage your dog’s environmental allergies, there is no excuse not to get outside and enjoy the beautiful weather. Just remember to wipe down dirty paws and claws before coming back inside!