Top 5 Canine Atopic Dermatitis Myths
Sponsored by Hill's Pet Nutrition
Canine atopic dermatitis (CAD) is a complex disease involving both immune dysregulation and structural abnormalities in the skin barrier, yet the role of the skin barrier may be underappreciated in clinical practice.1 The epidermal barrier, specifically the stratum corneum, serves as the body’s first line of defense against environmental allergens, microbes, and irritants.2 In dogs with CAD, structural and immunologic abnormalities weaken this barrier, allowing increased allergen penetration and promoting the chronic inflammation and pruritus that characterize CAD.3 Understanding how these processes interact and addressing common misconceptions about skin barrier management can help veterinarians develop more targeted, effective treatment strategies.
Below are 5 frequent misconceptions regarding CAD and information to dispel those myths.
Myth #1: Canine Atopic Dermatitis Is Caused by an Overactive Immune System
Although immune dysregulation is a key component of CAD, it is not the sole driver. CAD is multifactorial and is thought to result from a variety of factors. It comprises 2 distinct characteristics: skin barrier dysfunction and an overactive immune response.1 Historically, these mechanisms were thought of as competing hypotheses: the outside-in hypothesis versus the inside-out hypothesis.1
Outside-in hypothesis: Structural abnormalities in the skin barrier allow allergens and bacteria to penetrate through the stratum corneum more easily. Increased allergen exposure can trigger inflammation and pruritus, and the resulting itch–scratch cycle further damages the skin barrier.1
Inside-out hypothesis: Dogs with CAD have immune dysregulation that causes inflammation that subsequently damages the skin barrier.1,3
Current understanding suggests a combination of these theories, favoring the “outside-inside-outside” hypothesis in which both skin barrier and immune defects are at play.4
Myth #2: Nutrition Is Only Used to Support Dogs With Food Allergies, Not Canine Atopic Dermatitis
Nutrition is commonly discussed in the context of cutaneous adverse food reactions, but it can also play an important role in the management of CAD. Several nutrients contribute to maintaining the integrity and function of the skin barrier. Foods enriched with fatty acids (eg, linoleic acid, eicosapentaenoic acid, docosahexaenoic acid) and antioxidants (eg, zinc, vitamins C and E) may help support skin health and modulate inflammatory pathways.3,5-9 In some studies, dogs with CAD fed diets enriched with these nutrients showed improvements in pruritus and skin condition as reported by both veterinarians and pet owners.5,7,8
Therapeutic foods formulated for dermatologic conditions often incorporate these nutrients in targeted concentrations to support skin barrier function and help modulate inflammatory responses. For example, Hill’s Prescription Diet Derm Complete is designed to strengthen the skin barrier while helping to normalize the immune response to environmental allergens through a combination of high levels of essential fatty acids, use of a single intact animal protein (ie, egg), and a proprietary complex of bioactives and phytonutrients.10
Myth #3: The Primary Treatment for CAD Is the Use of Either a Janus Kinase Inhibitor or Monoclonal Antibody
The growing availability of targeted therapies such as Janus kinase (JAK) inhibitors and monoclonal antibodies has significantly improved the management of CAD.11 However, these therapies are rarely sufficient as standalone treatments.12
Because CAD involves both immune dysregulation and barrier dysfunction, most patients benefit from a multimodal treatment approach that addresses both “inside-out” and “outside-in” disease mechanisms.12
Common components of a multimodal treatment plan include:
Allergen-specific immunotherapy: Allergen-specific immunotherapy is a customized treatment that can help decrease a pet’s sensitivity to specific allergens. It is considered effective in >50% of CAD patients.12,13
Systemic therapies: JAK inhibitors (eg, oclacitinib) or monoclonal antibodies that neutralize interleukin-31 (ie, lokivetmab) can disrupt the itch signal.12 Other systemic therapy options include glucocorticoids or immunosuppressants (eg, cyclosporine).
Topicals: Routine bathing with shampoos that contain moisturizing factors like fatty acids, oatmeal, and/or ceramides can be helpful in improving the skin barrier.12 The use of topical treatments with antimicrobial factors like chlorhexidine should be considered in dogs with recurrent skin infections.12
Nutritional Support: Veterinary-formulated foods or supplementation with essential fatty acids may help support skin barrier health and modulate inflammation.1,12
Parasite control: Although parasite control does not directly treat CAD, strict flea prevention is essential for atopic dogs, as even minor infestations can trigger dermatologic flares.12
Myth #4: Detailed Client Education Is Only Critical for Dogs Undergoing a Food Elimination Trial
Client education is crucial when performing elimination diet trials, but it is equally important for the long-term management of CAD. Clients need to understand that CAD is a chronic, lifelong condition and most patients require ongoing therapy.12 Even with good control, occasional flares can be expected. It is best to set clear expectations for pet owners during initial visits to address skin disease, as the process of diagnosing and managing atopic skin conditions can be lengthy and frustrating.12
Education is also particularly important when discussing nutritional strategies. If a prescription dermatologic food is recommended for skin barrier support but their dog has not been diagnosed with a food allergy, owners may question its purpose. Explaining how specific nutrients support barrier function and help modulate inflammation can improve understanding and adherence to treatment plans.
Myth #5: Topical Therapies Are Not an Important Tool in Managing Canine Atopic Dermatitis
Topical therapies are sometimes overlooked in CAD management, but as mentioned, they can play an important role in improving skin barrier function and helping to remove potential allergens from the skin surface. Frequent bathing with appropriate shampoos can help remove environmental allergens, reduce microbial overgrowth, and hydrate the skin.3 A range of topical products (eg, spot-ons, sprays, and shampoos) feature lipid-based ingredients such as essential fatty acids, cholesterol, ceramides, and phytosphingosine (a ceramide precursor), formulated with the goal of rebuilding and supporting epidermal barrier function.3
Conclusion
CAD is a complex disease involving both immune dysregulation and structural abnormalities in the skin barrier. Recognizing the interplay between these processes can help clinicians develop treatment plans that address both the underlying inflammation and the integrity of the skin barrier. A multimodal approach that includes systemic therapy, topical management, nutritional support, and client education can help optimize outcomes for dogs living with this chronic condition.
