Canine Atopic Dermatitis
Last updated: February 2020
When most people have seasonal allergies, they have "hay fever" -- mostly upper respiratory symptoms. Dogs with seasonal environmental allergies almost always manifest with atopic dermatitis. As a veterinarian (and a parent of a child with atopic dermatitis), I am very familiar with this presentation of the disease!
Dogs with atopic dermatitis can have erythema (red skin), flakes and dandruff, crusts and pustules, and lots of itching. They can also get ear infections (otitis externa) and may lick the bottoms of their itchy feet so much that they get pododermatitis (inflamed, infected feet).
Is treatment different for dogs?
For canine patients, most of the treatments are not topical, for a big hairy reason! Dogs are covered with hair, which makes topical treatments difficult and messy. Many of my clients also complain that their dogs lick off any topicals, so we don't often treat that route. We do have some medicated shampoos, but their effect is transient. Once the product is washed away, they don't have much action on the skin anymore. There are some helpful shampoos with microemulsions (such as Duoxo) which can have a longer effect, but still require bathing or spraying several times per week.
The traditional treatments for canine atopic dermatitis have been steroids, sometimes combined with oral antibiotics if a secondary infection is contributing to the inflammation. Steroids can be inexpensive and quickly effective at stopping the itch.
However, steroids come with some serious and undesirable side effects, and long-term use should be avoided. They may be absolutely necessary, however, in acute inflammatory situations. They can be helpful in getting itch under control while other treatments are getting started. Your veterinarian can determine when steroids are appropriate.
New treatments on the horizon
There are some very exciting new prescription treatments for canine atopic dermatitis. Apoquel is a prescription pill that stops part of the itching cascade in dogs. It is given daily, then may be decreased.
Cytopoint is an injectable medication that stops another pathway in the canine itch cycle, and it lasts for a month. Neither of these medications have the bad side effects that steroids have. Unfortunately for us, neither of them have applications in human medicine. Not every dog responds perfectly to either medication, but these have been revolutionary for many atopic dogs.
Dogs can be given antihistamines, including some over-the-counter products, but always check with your veterinarian before giving for the dose and safety. Sadly, antihistamines are not as effective in dogs as they are in people. Dogs also can get hyposensitization injections, similar to human "allergy shots," but again with variable limited efficacy.
Food allergies in dogs
While some dogs do have a food allergy component to their atopic dermatitis, the incidence is much lower than to environmental allergens. You can't just switch their food brand; you need to consult with your veterinarian about doing a complete food trial with a novel protein source and novel carbohydrate source. The protein source (chicken, beef, pork, etc) is nearly always the culprit, rarely the carbohydrate. Grain-free dog foods are not hypoallergenic. In fact, there is no specific disease process in dogs related to eating grain as there is in humans. Grain-free is a marketing term, not a medical term. Your veterinarian can tell you more and guide you to an appropriate diet for your dog.
Lastly, most atopic dogs are also allergic to flea bites. Make sure that your dog is on a safe, effective parasite control (usually monthly) recommended by your veterinarian.
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