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Written by Vet Evidence Based

Canine Atopic Dermatitis: Causes, Symptoms, and Treatments

Margarita Boyd
Written by: Dr. Margarita Boyd, BVSc MRCVS
Learn about the symptoms and treatmentas of atopic dermatitis in dogs. Discover how common this skin disorder is and how you can help your canine go through it.

Atopic dermatitis is an allergic skin disease in dogs, which causes the skin to become red and very itchy. It’s also known as atopy, or canine eczema.

This common disease is thought to affect a whopping 10-15% of the canine population and usually develops between the age of 6 months and 3 years.(1) Let’s take a closer look at the clinical signs, diagnosis and if there are any treatment options for this serious canine condition.(2)

What Are The Signs Of Atopic Dermatitis?

It is not surprising to learn that atopic dermatitis can be a painful and stressful condition. The main sign is itchiness and the constant urge to lick, scratch and rub cannot be very comfortable for the dog, or the owner who has to watch helplessly. The most commonly affected areas are the ears, feet, armpits, groin and tummy.(3)

Symptoms may start mildly, then become worse over time as the dog continues to itch and damage it’s skin. Here are some common signs of atopic dermatitis in dogs that you should watch out for:

  • Itching: Licking, chewing, biting or rubbing
  • Shaking the head
  • Redness of the skin
  • Rashes
  • Hair loss
  • Darkening of the skin
  • Recurrent skin infections
  • Ear infections
  • An unusual smell

Now you know the signs to watch out for, you will want to know what causes this condition.

What Causes Atopic Dermatitis?

Most cases are caused by the dog’s immune system over reacting to common substances (allergens) in the environment, causing the dog to have an allergic reaction.

Whether your dog develops atopic dermatitis or not, is due to a combination of your dog’s genetics and the environmental allergens he is exposed to. A healthy dog’s skin acts as a barrier to help protect the body, and keep out unwanted substances. In dogs with atopic dermatitis their skin barrier becomes weak and starts to dysfunction, allowing the allergens into the body.(4)

What Are Allergens?

An allergen is a substance that is recognized by the dog’s immune system as foreign and causes an allergic reaction. Almost any substance your dog comes into contact with can act as an allergen.

Environmental allergens are literally everywhere and some are impossible to completely avoid. Depending on the allergens involved, the itching may be seasonal (e.g. pollen) or non-seasonal (e.g. food).(5)

Common allergens include:

  • House dust mites
  • Storage mites
  • Grass/weed/tree pollens
  • Molds
  • Medication
  • Food
  • Insect bites

Can Fleas Cause Atopic Dermatitis?

Fleas don’t normally cause atopic dermatitis, but they can make the condition much worse. The thought of fleas will make most people squirm, imagine how your dog feels. The signs of a dog with fleas and atopic dermatitis can be very similar. That’s why it is really important if you notice your dog itching that you or your veterinarian check your dog’s coat thoroughly for fleas.

Are Some Breeds More Prone To Atopic Dermatitis Than Others?

Yes, some breeds are more prone to this disease than others. It is a hereditary condition, meaning it can be passed down from the parent dogs to their offspring.

By now you might be wondering if your dog is at risk of this disease. Studies have shown that some breeds of dog are at a higher risk of developing this condition: (6)

Is Atopic Dermatitis Easy To Diagnose?

The diagnosis of this disease can be a challenge, as lots of conditions can cause a dog to be itchy. On top of that the clinical signs of atopic dermatitis will vary from dog to dog.

There is no single test that can give a quick diagnosis. That’s why if you think your dog has atopic dermatitis you should book an appointment with your veterinarian.

How Does A Veterinarian Diagnose Atopic Dermatitis?

A veterinarian will usually focus on three main components in order to make a diagnosis:

  1. Take a detailed history and complete a full clinical examination of the dog
  2. The vet will ask you lots of questions about your dog such as when the itching started, where does your dog itch, if your dog is showing any other signs of sickness, what your dog eats or if you recently changed your dog’s bedding or laundry detergent. Then the vet should fully examine your pet from head to toe and record where the skin is sore and any other findings. Together these help the vet narrow down the possible causes of itching.

  3. Rule out other skin conditions which can have similar clinical signs
  4. This involves checking for evidence of parasites (e.g. fleas, mites), skin infections (e.g. bacteria, yeast) or cancer. The vet may use a flea comb, or take some samples from the dog’s skin, hair or ears to examine under a microscope, or send to a laboratory. The vet may also advise a diet trial for your pooch (more on that later).

  5. Allergy testing
  6. Once the vet has ruled out other possible causes of itching, then they might consider allergy testing. These tests are not 100% accurate but can still be very useful to help identify what a dog might be allergic to and then the owner can try to avoid it. (7)

    Intradermal test: The dog has a patch of hair shaved and the top layer of skin is pricked with a tiny amount of different allergens. Each small prick area is observed for an allergic reaction.

    Blood test: A blood sample is taken from the dog and sent to a special laboratory. It is checked for specific IgE antigens (what the dog produces when he has an allergic reaction) against a panel of possible allergens.

Can A Change In Diet Help?

Yes, often a dog with atopic dermatitis can benefit from a diet trial or a change in diet.

Food allergies often cause tummy upsets such as vomiting and diarrhea, but sometimes they can cause a skin rash and itchiness. Common food allergens include chicken, beef, wheat, dairy, egg, lamb or soy 10.

A diet trial consists of feeding a strict hypoallergenic diet for at least 8 weeks, with no treats or human food. If the dog’s clinical signs improve then it probably has a food allergy causing the dermatitis. You might think a food trial is too difficult to carry out, but imagine giving your dog lots of unnecessary medication for the rest of it’s life, when a diet change could have solved the problem.

Even if a food allergen is not causing a dog’s atopic dermatitis, a change to a high quality, natural diet can still help to boost the dog’s immune system and overall skin health. Supplementing a dog’s diet with essential fatty acids has been shown to improve the dog’s skin and coat, and may help the long term control of atopic dermatitis.(8) Alternatively talk to your veterinarian or canine nutritionist about a switch to a complete raw diet or a hypoallergenic diet.

How Is Atopic Dermatitis Treated?

There are lots of different treatment options available for atopic dermatitis, depending on how long the dog has had the problem, how sore and itchy the dog’s skin is and what allergens are causing the problem.

Conventional treatment aims to reduce the dog’s allergic reaction using immunosuppressants, to quickly reduce the itchiness and redness of the skin. Usually a soothing antibacterial shampoo is advised during flare ups too. For good long term control of atopic dermatitis, injectable immunotherapy or antibody therapy is often recommended.

Let’s take a closer look at some of the treatment options. Often a dog will need a combination of different medications to control this condition.


Medications such as corticosteroids or antihistamines may be prescribed to quickly control or reduce the redness, itching and inflammation. However, corticosteroids can have some major side effects, especially if used long term, including: increased thirst and urination, hair changes, weight gain or even cause Cushing’s disease. Oclacitinib (Apoquel, Zoetis) or cyclosporine are other types of immunosuppressant medications which may be used long term with less side effects. Always talk to your veterinarian about the possible risks with each treatment option.

Antibody Therapy

Cytopoint (lokivetmab, Zoetis) is a newer treatment option which works by blocking the itch signal sent to the brain in chronic atopic dermatitis.(9) It is an injection which acts for 4-8 weeks, and studies have shown it to have minimal side effects.(10)


This involves producing a personalised vaccine for the dog against the allergens that are causing the disease. The dog is injected regularly with tiny amounts of the allergens, which builds immunity to the allergens over time.

Treat Infections

It is common for dogs with atopic dermatitis to have other skin infections present too, such as bacterial or yeast infections. These often make your dog have a very bad odor! These infections will need to be treated with a course of tablets, a topical cream or a medicated shampoo.

Medicated Shampoo

Regular bathing often helps to make the dog feel more comfortable and soothe the skin. An antibacterial shampoo, or a soothing shampoo with ceramides (to help rebuild the skin barrier) is often recommended.(11) Don’t be tempted to use a regular human shampoo- it will just make the dog’s skin worse.

Regular Flea Treatment

These tiny insects can cause lots of problems, such as causing sores when they bite the skin and making a dog go crazy with the itch. They can also make a case of atopic dermatitis much worse, as the dog’s skin is so sensitive. Routine flea treatment is usually advised to make sure no flea visitors cause any additional issues.

Can Allergens Be Avoided?

Allergen avoidance is one of the best and cheapest ways to improve atopic dermatitis. However, some allergens can be pretty impossible for a dog to avoid!

If dust mites are the problem, then the dog should not have access to the bedrooms (where dust mite levels are highest), should use hypoallergenic bedding, the home should be vacuumed very regularly, and all bedding washed regularly at high temperatures to kill mites.

If pollen is the problem, it can be difficult to avoid as it can travel in the wind for miles. Restrict the dog’s access to long grass and meadows and rinse the dog off after walks to remove pollen from the hair.

Can Atopic Dermatitis Be Cured?

No, unfortunately atopic dermatitis cannot be cured. This is a chronic skin condition which needs to be managed for the rest of the dog’s life. However, don’t despair quite yet as with proper diagnosis and effective management many dogs go on to have normal lives.

Can This Condition Be Prevented?

Recent research has started to focus on how this chronic condition can be prevented. Some studies have found that a pup that is reared in a rural environment has less chance of developing atopic dermatitis5. Additional studies have found that dogs living with other dogs living in a rural area and feeding a home made diet to lactating mother dogs are all protective factors.(12)

Although this research won’t help make your pet better if he suffers from atopic dermatitis, it is good news for future generations to help prevent it happening to future pups!


By now it is pretty obvious that atopic dermatitis is a frustrating disease, and the constant itch can be both painful and stressful for the dog. However, with proper treatment and monitoring, the majority of cases can be well controlled and affected dogs can go on to live normal lives.

As it is a life long condition, dogs will require constant monitoring, and regular check ups with a veterinary dermatologist are recommended.