Atopic dermatitis in dogs: symptoms and treatment

If your dog won't stop scratching, licking their paws or rubbing their face along the carpet, it can be worrying and exhausting for both of you. One of the most common reasons for this kind of persistent itching is atopic dermatitis, sometimes called atopy or environmental allergy. It's not something you've done wrong, and it's very manageable once you understand what's driving it.

Atopic dermatitis is a long-term skin condition caused by an allergic reaction to things in your dog's everyday environment, such as pollen, dust mites or mould spores. It isn't contagious and it isn't caused by poor hygiene. It is, however, a lifelong condition, so the goal of treatment is control and comfort rather than a permanent cure.

The good news is that most dogs with atopic dermatitis go on to live full, happy lives once a management plan is in place. This guide explains what's actually happening in your dog's skin, the signs to watch for, how vets reach a diagnosis, and the treatment options available in the UK today.

What is atopic dermatitis?

Atopic dermatitis is an inflammatory, itchy skin disease caused by a combination of genetics and environment. According to PDSA, it's an allergy to something in the environment such as pollen, moulds, grass or dust mites, and it's thought to affect a significant proportion of dogs seen by vets for skin problems.

Cornell University's Riney Canine Health Center describes it as a common skin disease that may affect as much as 10-15% of the dog population. VCA Animal Hospitals gives a similar figure, noting that around 10-15% of dogs seen by veterinary dermatologists receive an atopy diagnosis.

Crucially, affected dogs are born with a defective skin barrier. In a healthy dog, the outermost layer of skin (the epidermis) keeps allergens out. In a dog with atopic dermatitis, this barrier is imperfect, allowing environmental allergens to penetrate the skin and trigger an exaggerated immune response. This is different from how allergies usually work in people, where pollen allergies tend to cause sneezing and watery eyes; in dogs the same allergens usually show up as skin inflammation and itching instead.

What causes it

Atopic dermatitis develops because of an interaction between a dog's genes and things in their surroundings. Common triggers include:

• House dust mites - often the biggest year-round trigger
• Pollens from grass, trees, and weeds
• Mould spores
• Dander from other animals

Most affected dogs aren't reacting to just one thing. As PDSA points out, most dogs with allergic skin disease are allergic to more than one substance, which is part of why triggers can be so hard to pin down and why complete avoidance usually isn't realistic.

There's also a clear genetic element. Cornell lists commonly affected breeds as including Labrador Retrievers, Golden Retrievers, Soft-Coated Wheaten Terriers, West Highland White Terriers, Jack Russell Terriers, Bulldogs, Boston Terriers, Boxers, Shar Peis, Shih Tzus and Weimaraners. VCA's breed list overlaps closely, also naming French Bulldogs, German Shepherds, Cocker Spaniels and Poodles as predisposed. Animal Trust separately highlights the West Highland White Terrier, Bichon Frise and Shar Pei as particularly susceptible. If you own one of these breeds, it doesn't mean your dog will definitely develop atopic dermatitis, but it's worth being alert to early signs.

Age of onset is fairly consistent across sources too: Cornell and PDSA both note that signs typically start when a dog is young, generally between 6 months and 3 years old. A dog developing itchy skin for the first time well into middle or old age is more likely to have a different cause, which is one reason your vet will want to examine them properly rather than assume it's atopy.

Recognising the symptoms

The hallmark sign of atopic dermatitis is pruritus, meaning persistent itchiness, but it shows up in a range of behaviours and physical changes rather than just obvious scratching. Look out for:

• Scratching, especially around the armpits, groin, and behind the elbows
• Constant licking or chewing at the paws
• Rubbing the face along furniture or carpet
• Recurrent ear infections or head shaking
• Red, inflamed skin
• Hair loss in itchy areas
• Reddish-brown saliva staining on light-coloured fur, especially around the paws and muzzle
• Thickened, darkened, elephant-like skin in chronically affected areas
• A greasy feel or unpleasant smell to the coat, often a sign of secondary infection

VCA notes that the face, ears, paws, and the flexor areas (armpits, groin, and the inside of the elbows) are typically the worst affected. Cornell adds that itchiness often has a seasonal pattern in 40-75% of cases, meaning it may flare up in spring and summer when pollen counts are high, then ease off in winter. Over time, though, many dogs' symptoms become year-round as dust mites and other indoor allergens take over as the dominant trigger.

It's also very common for atopic dogs to develop secondary skin and ear infections. Constant scratching and licking damage the skin's surface, letting bacteria and yeast that normally live harmlessly on the skin multiply out of control. This is often what turns a mildly itchy dog into one with smelly, greasy, sore skin that needs antibiotics or antifungal treatment on top of allergy management.

Most dogs with allergic skin disease are allergic to more than one thing, which is why treatment usually focuses on controlling the itch rather than eliminating every possible trigger.

How vets diagnose atopic dermatitis

Here's the part that surprises a lot of owners: there is no single test that confirms atopic dermatitis. Both Cornell and Animal Trust are explicit about this: atopy is what's known as a "diagnosis of exclusion". Your vet builds the diagnosis by ruling out every other possible cause of itchy skin first, then arriving at atopic dermatitis by process of elimination alongside a compatible history and pattern of symptoms.

Section by section, this typically means examining and ruling out the following.

Parasites

Fleas are a very common cause of itching, and some dogs are specifically allergic to flea saliva (flea allergy dermatitis), so your vet will want your dog on strict, vet-recommended flea prevention before considering atopy. Skin scrapes may also be taken to rule out mites such as those causing sarcoptic mange.

Food allergy

Because food allergies can produce identical symptoms to environmental atopy, your vet may recommend an elimination diet trial. PDSA and Animal Trust both describe this as typically running for 6 to 12 weeks, using a novel or hydrolysed protein diet with absolutely no other treats, table scraps or flavoured medications during the trial period, before challenge-testing with the original diet to see if symptoms return.

Infections

Bacterial and yeast infections of the skin and ears are ruled out or treated alongside the underlying allergy, since they can mimic or worsen allergic symptoms.

Allergy testing

Once other causes are excluded, your vet may refer you to a veterinary dermatologist for allergy testing, either intradermal skin testing (injecting small amounts of specific allergens into the skin and watching for a reaction) or blood (serologic) testing. Both PDSA and VCA note that these tests are useful for identifying specific triggers, particularly to guide immunotherapy, but neither is 100% reliable on its own and results are always interpreted alongside your dog's history and symptoms.

Treatment options

Because atopic dermatitis has no cure, treatment is described by every source as lifelong and usually multi-modal, meaning a combination of approaches, rather than a single medication, tends to work best. Your vet will build a plan around your individual dog, their triggers, and how severe their symptoms are.

Trigger avoidance

Where a specific trigger is known, such as house dust mites, reducing exposure can help. Practical steps include frequent vacuuming and washing bedding, and minimising exposure to freshly cut grass during peak pollen season. Strict, year-round flea control is recommended for every atopic dog, since flea bites make any existing itch far worse.

Topical treatments

Medicated shampoos, mousses, and wipes, often containing ceramides and fatty acids to rebuild the skin barrier, or mild antimicrobial ingredients to reduce surface bacteria and yeast, are frequently used as a first line of relief and to reduce reliance on other medication.

Anti-itch medication

Several prescription-only medications are available and your vet will choose based on your dog's age, health, and severity of symptoms. These include:

• Oclacitinib (Apoquel) - a fast-acting tablet that blocks the itch signal
• Lokivetmab (Cytopoint) - an injectable antibody treatment, typically given every 4-8 weeks
• Ciclosporin (Atopica) - a longer-acting immune-modulating tablet
• Corticosteroids such as prednisolone, effective but usually reserved for short-term or flare-up use because of side effects with long-term dosing
• Antihistamines, generally milder in effect, sometimes used alongside other treatments

Your vet is best placed to decide which of these, if any, suits your dog. Do not give any human antihistamine or steroid to your dog without veterinary guidance, as doses and suitable drugs differ from those used in people.

Immunotherapy

Also called desensitisation, this involves giving gradually increasing amounts of the specific allergens your dog reacts to, either by injection or as drops under the tongue, over a period of months to years. Cornell and PDSA both note this can meaningfully reduce itching in a good proportion of dogs, though it doesn't work for every dog and requires patience, since benefits can take three to twelve months or longer to appear.

Supplements

Omega-3 and omega-6 fatty acid supplements are commonly recommended alongside other treatments to help support the skin barrier and reduce inflammation, though they're rarely enough as a sole treatment for moderate to severe cases.

Managing secondary infections

When bacterial or yeast infections take hold, your vet will usually prescribe a course of oral or topical antibiotics or antifungals. Treating these promptly is important, since untreated infections keep the itch-scratch cycle going even if the underlying allergy is otherwise well controlled.

Living with a dog with atopic dermatitis

Once a management plan is in place, most owners find their dog's quality of life improves dramatically, even though the underlying allergy never fully goes away. A few practical habits make a real difference:

• Stick to a consistent flea prevention schedule year-round, not just in summer
• Keep to the prescribed bathing routine, even when skin looks clear, as it's often preventing the next flare-up
• Avoid changing food, treats, or bedding without checking with your vet, especially if a food trial is underway
• Keep a simple diary of flare-ups and possible triggers (weather, walks, new products) to help your vet fine-tune the plan
• Book regular check-ups rather than waiting for a bad flare, since catching secondary infections early is far easier than treating an established one

If your dog is a breed prone to skin sensitivity, a Pet Ownership Quiz can help you think through the day-to-day care commitment before bringing a new dog home, and our Pet Calorie Calculator can help if your vet recommends a specific hypoallergenic diet and you want to check portion sizes are right for your dog's weight.

When to see your vet

See your vet if your dog is scratching, licking, or rubbing more than usual, especially if it's persistent rather than a one-off itch. You should also contact your vet promptly if you notice:

• Red, sore, or smelly skin
• Hair loss or bald patches
• Repeated ear infections or head shaking
• Skin that looks thickened, darkened, or greasy
• Symptoms that are getting worse despite home care

Skin conditions like this tend to get worse, not better, if left untreated, and early diagnosis makes it far easier to find an effective, comfortable long-term plan for your dog.

*This is general guidance, not a substitute for advice from your vet, who can assess your individual pet.*

Sources - PDSA - skin allergies (atopic dermatitis) in dogs (pdsa.org.uk). - VCA Animal Hospitals - inhalant allergies (atopy) in dogs (vcahospitals.com). - Animal Trust - atopic dermatitis in dogs (animaltrust.org.uk). - Cornell University Riney Canine Health Center - atopic dermatitis (atopy) (vet.cornell.edu).