Atopic dermatitis in dogs is a chronic, itchy, inflammatory skin disease linked to allergies. Dogs inherit the tendency to develop it, and their skin reacts to everyday allergens, most often house dust mites and pollens. It can't be cured, but in most dogs it can be managed with long-term care that your veterinarian plans.
If your dog keeps scratching, licking its paws or getting ear infections, or you notice changes in its skin, contact your veterinarian. Several itchy skin diseases look alike, so treatment depends on what your veterinarian finds and is chosen by your veterinarian.
What is Atopic Dermatitis in Dogs?
Skin inflammation is one of the most common problems that afflict dogs, and "dermatitis" simply means inflamed skin. Fleas, mites, infections, food reactions and contact with irritants can all cause it. Atopic dermatitis (AD, also called atopy) is one specific, inherited form of allergic skin disease.
The current international definition, quoted in the Merck Veterinary Manual, describes it as a hereditary, typically itchy skin disease driven by the immune system. Three things interact:
- A weak skin barrier, which lets allergens get into the skin more easily.
- Allergen sensitization, usually IgE antibodies against environmental allergens, food or microbes.
- An imbalance of skin microbes, the bacteria and yeast that normally live on the skin.
The main environmental allergens are house dust mites and pollens. In some dogs, food ingredients also play a part. Flea bites don't cause atopic dermatitis, but they are a common trigger for flares in a dog that already has it.
For vets and techs: some dogs look exactly like atopic dogs but have no detectable IgE sensitization. Merck calls this atopic-like dermatitis.
Which Dogs Get Atopic Dermatitis?
Signs usually start young. Merck puts the age of onset generally between 6 months and 3 years, with no difference between males and females.
Any dog can be affected, but some breeds are predisposed, including the Boston Terrier, Boxer, Chinese Shar-Pei, Dalmatian, Golden Retriever, Labrador Retriever, Lhasa Apso, Scottish Terrier, Shih Tzu, West Highland White Terrier and Wire Fox Terrier. Breed risk isn't fixed, though. How common AD is within a breed depends largely on its genetic pool and on the region.
Timing depends on the allergen, not the breed. Pollen allergies tend to cause seasonal itch. Dust mites and food cause itch all year. Many dogs have both: year-round itch that gets worse in certain seasons.
Signs of Atopic Dermatitis in Dogs
Itch (pruritus) is the hallmark. Early on, a dog may itch without any visible skin changes. Watch for:
- Scratching and rubbing
- Licking or chewing the paws
- Excessive grooming or licking
- Scooting
- Head shaking
Most of the skin changes you see come from the scratching itself or from infection that follows. They include redness, hair loss, scaling, crusts, scratch wounds, darkened skin, and lichenification (thickened, leathery skin from months of rubbing).
Where it shows up
The paws, face, ears, the inner (flexural) surfaces of the front legs, the armpits and the belly are the areas most often affected. The groin and the area around the anus can be involved too, and the pattern varies by breed.
Ear and skin infections
Secondary bacterial (Staphylococcus) and yeast (Malassezia) infections of the skin and ears are common in atopic dogs. A bad smell or discharge usually points to infection on top of the allergy. In a small number of dogs, chronic or recurring ear infections are the only sign. If your dog's ear infections keep coming back, ask your veterinarian whether allergy could be behind them. Our guide to pyoderma in dogs covers the bacterial side.
When to see your vet: persistent itching, paw licking that won't stop, repeat ear infections, open sores, or a smell from the skin or ears are all reasons to book a visit.
How Vets Diagnose Atopic Dermatitis
There is no single test for atopic dermatitis. According to Merck, the diagnosis rests on the dog's age, breed, history and signs, plus ruling out other itchy skin diseases. It doesn't come from a lab result.
That usually means working through the look-alikes first:
- Parasites. Your vet checks for fleas (flea combing) and mites (skin scrapings). Fleas are insects, not mites, and flea allergy dermatitis is one of the conditions that can look like atopic dermatitis.
- Infection. Cytology, looking at skin or ear samples under the microscope, shows bacteria or yeast that need treatment.
- Food. Dogs that itch year-round or also have stomach or bowel signs need a strict elimination diet trial (a special diet with nothing else, supervised by your vet) to rule out a food reaction.
Conditions that can look like atopic dermatitis
- Parasites: fleas, scabies (sarcoptic mange), demodicosis, Cheyletiella, lice, ear mites
- Infections: staphylococcal pyoderma, Malassezia (yeast) dermatitis
- Other allergies: flea allergy, food reactions, insect bite hypersensitivity, contact dermatitis
- Other diseases: autoimmune skin disease, hypothyroidism, hyperadrenocorticism (Cushing's), keratinization disorders, cutaneous lymphoma
Favrot's criteria: a guide, not a test
Once the look-alikes are ruled out, many vets use Favrot's criteria to judge how well a dog fits the typical pattern. The ICADA diagnosis guidelines list them as:
- Signs started before 3 years of age
- Dog lives mostly indoors
- Itch that responds to corticosteroids
- Chronic or recurrent yeast infections
- Front feet affected
- Ear flaps (pinnae) affected
- Ear margins not affected
- Area over the lower back not affected
ICADA reports that using 5 of the 8 criteria as the cutoff gives a sensitivity of 85.4% and a specificity of 79.1%. That's useful, but it also means some atopic dogs miss the cutoff and some dogs with other itchy skin diseases pass it. ICADA says the criteria should not be used on their own as a diagnostic test, and Merck notes they don't apply to food-induced atopic dermatitis.
What allergy tests are actually for
Intradermal (skin) tests and blood (serum) allergy tests don't diagnose atopic dermatitis. A positive result reflects what a dog has been exposed to, not proof that those allergens are causing its skin disease. ICADA advises against using these tests for screening. Their real job comes after the diagnosis: identifying which allergens to include in allergen-specific immunotherapy.
Treatment and Long-Term Management
Atopic dermatitis can't be cured, but in most dogs it can be managed. Merck describes it as a chronic disease that needs lifelong management and regular progress checks. The plan usually has two parts: calming a flare when it happens, and keeping the dog comfortable between flares. Your veterinarian chooses the products, doses and schedule for your dog.
Controlling the itch
Several drug classes are used to relieve itch and inflammation:
- Glucocorticoids (steroids), topical or oral. They work fast. Long-term oral use carries a high risk of side effects, which is why they need close veterinary supervision.
- JAK inhibitors, such as oclacitinib and ilunocitinib. These are fast-acting anti-itch drugs.
- Lokivetmab, an antibody that targets IL-31, a signaling molecule involved in itch. It is also fast-acting.
- Cyclosporine, an immune-modulating drug that is slow to take effect and is used for long-term control rather than sudden flares.
- Antihistamines, which do little during an acute flare and offer at most a small benefit in some dogs as part of ongoing care.
If a dog doesn't respond quickly to a glucocorticoid or oclacitinib, ICADA advises reconsidering the diagnosis or looking for complications such as infection.
Allergen-specific immunotherapy (ASIT)
Allergen-specific immunotherapy is a long-term treatment, given by injection or by mouth, that is built from a dog's allergy test results. According to Merck, it is the only atopic dermatitis treatment that can change the immune response to allergens and induce remission, and it is the treatment of choice of most veterinary dermatologists. It is slow to work, so it doesn't help with an acute flare. Along with proactive intermittent topical glucocorticoids, ICADA names it as one of the only interventions likely to prevent or delay flares.
Treating secondary infections
Antibiotics and antifungals don't treat atopic dermatitis itself. They are used when your vet diagnoses a bacterial or yeast infection of the skin or ears, based on the signs and often confirmed with cytology or a culture. Infections are also a common flare factor, so finding and treating them matters.
Skin barrier care and flare control
- Bathing. Bathing with a mild shampoo can lower the allergen load on the skin. ICADA notes that how often and how thoroughly a dog is bathed may matter most for the itch relief bathing gives. Your vet will tell you which shampoo to use and how often, since some shampoos irritate atopic skin.
- Fatty acids and skin-barrier products. These can be add-ons for ongoing care but are slow to act and don't control a flare.
- Flea control. ICADA recommends that dogs with atopic dermatitis receive effective flea control year-round, because flea bites trigger flares.
- Allergen reduction. Lowering exposure to the dog's known allergens, where practical, can help reduce flares.
Living With an Atopic Dog
Flares can happen even in well-managed dogs, for example during pollen season, after flea bites, or when an infection takes hold. Regular rechecks let your veterinarian adjust the plan as the dog's needs change. Between visits, it helps to note when the itch gets worse, which body areas are involved, and any smell, discharge or new sores, then share that with your vet.
Sources
- Merck Veterinary Manual: Atopic Dermatitis in Dogs
- BMC Veterinary Research: Canine atopic dermatitis: detailed guidelines for diagnosis and allergen identification (ICADA, Hensel et al., 2015)
- BMC Veterinary Research: Treatment of canine atopic dermatitis: 2015 updated guidelines from ICADA (Olivry et al.)
This article is for general information and is not a substitute for advice from your veterinarian.
