What Is Canine Atopic Dermatitis?
Canine atopic dermatitis (CAD) is a chronic, genetically predisposed inflammatory skin disease driven by an exaggerated immune response to environmental allergens: house dust mites (Dermatophagoides), grass and tree pollens, mould spores and animal dander. It is the second most common cause of itching in dogs after flea allergy.
Symptoms: The Atopy Triad
- Pruritus — the cardinal sign. Scratching, paw licking, face rubbing.
- Characteristic distribution — face (muzzle, eyes), paws (between the toes), armpits, groin and skin folds.
- Recurrent otitis externa — chronic ear canal inflammation, often with secondary Malassezia or bacterial infections.
Diagnosis
There is no single definitive test. Diagnosis is clinical + by exclusion:
- Rule out other causes of itching: fleas (FAD), sarcoptic mange, food allergy.
- Apply the Favrot criteria (standardised clinical scoring).
- Intradermal or serum IgE allergy testing to identify allergens for immunotherapy.
Treatment
- Oclacitinib (Apoquel) — JAK1 inhibitor. Fast onset (4 hours), highly effective for pruritus control. Daily oral tablet.
- Lokivetmab (Cytopoint) — anti-IL-31 monoclonal antibody (the "itch cytokine"). Monthly SC injection. Excellent safety profile.
- Ciclosporin (Atopica) — oral immunomodulator. Takes 4-6 weeks to work; good long-term maintenance option.
- Allergen-specific immunotherapy (ASIT) — the only disease-modifying option. A personalised vaccine is prepared from identified allergens and administered over years. Effective in 50-70 % of patients.
- Skin barrier care — frequent bathing with specialist shampoo (colloidal oatmeal, phytosphingosine), emollient application. Reduces allergen load and improves barrier function.
- Omega-3 fatty acids — EPA/DHA reduce inflammation and improve coat quality.
Environmental Control for Dust Mite Allergy
HEPA vacuum frequently, use mite-proof covers on mattresses and sofas, wash the dog's bed weekly at 60 °C. Avoid letting the dog sleep in the human bed.