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Atopic dermatitis (atopy) in dogs

photo of dog on white background


Atopic dermatitis (atopy) is an allergy to something in the environment (such as pollen, moulds, grass or dust mites).

Dogs with atopy tend to have very itchy skin, usually worst on the paws, ears, tummy and armpits. Constant scratching, licking and biting makes their skin red, sore and open to infection.

Treatment for atopy often includes a special diet, medication to stop the itch and skin supplements.

Without treatment, atopy can severely affect a dog’s quality of life but with proper treatment, dogs with atopy can live a long, happy life.

Food allergies and flea allergies cause skin problems with almost identical symptoms to those of atopic dermatitis.

What is atopy?

Atopy is a skin condition caused by an allergy to something breathed in from the environment such as pollens from trees or grass, moulds and dust mites.

Atopy can develop at any age and in any breed of dog, although it’s more common in young dogs and in certain breeds such as the West Highland White Terrier (Westie).

Food allergies and flea allergies cause almost identical symptoms to atopic dermatitis.

Symptoms of atopy

Photo of a dog with atopy

An atopic dog: note the dark, hairless, thickened skin.

What is my dog allergic to?

Common triggers include fleas, pollen, trees, moulds, dust mites, grass and cleaning products….the list goes on!

There are blood tests available to identify what your dog may be allergic to, but they don’t always give accurate results. Your vet may be able to offer or refer your dog to a specialist hospital for skin testing. Skin tests for allergies tend to be more reliable than blood tests.

Finding out exactly what your dog is allergic to can be quite challenging and it doesn’t always change the treatment your dog is given. Speak to your vet about the pros and cons of testing.

Your vet will want to rule out food allergies and flea allergies before diagnosing your dog with atopy because they both cause such similar symptoms to atopic dermatitis. If your dog turns out to be allergic to food or fleas this is generally much easier to treat than an allergy to something in the environment.

It’s actually very common for a dog to be allergic to lots of different things i.e. food as well as something in the environment.


Atopy needs lifelong management. There are three main ways to treat it:

Medical treatment

  • The aim of medical treatment is to control the symptoms, not cure the allergy.
  • Your vet may recommend:
    • Steroids and/or other ‘anti-itch’ medication. These will help stop the itch, make your dog feel more comfortable and allow their irritated skin to heal. There are a few different drugs available. They vary in how effective they are, how often they need to be given, their costs and side effects. Speak to your vet for more information.
    • Antibiotics - aren’t always necessary but may be used if your dog has a skin infection.
    • Ear drops may be used to treat ear infections.


  • If you have found out what your dog is allergic to by skin and/or blood testing, tailored vaccines (also called immunotherapy) can be made to reduce the allergic reaction they have to their triggers.
  • These vaccines need to be given very regularly throughout the rest of your dog’s life and work slowly over time. Your dog may take many weeks or even months to show improvements.
  • Immunotherapy doesn’t work for every dog and medication is often still needed to reduce symptoms.

Avoid allergy triggers

  • In an ideal world, we would treat atopic dermatitis by completely avoiding your dog’s allergy triggers. This would stop symptoms from developing.
  • Avoiding triggers is almost impossible if your dog is allergic to something in the environment. However, there are some sensible precautions you can take to ensure your dog develops as few symptoms as possible. Check out our ‘Ongoing care’ section below for more information.

Ongoing care at home

Avoid your dog’s triggers

  • The ideal treatment is to avoid what your dog is allergic to so that symptoms don’t develop. This is rarely possible for dogs with atopic dermatitis because their triggers are in the environment, all around them. You can help to reduce the chance of a flare-up by taking precautions such as:
    • Avoiding walks when the pollen count is high.
    • Rinsing your dog off after a walk in long grass.
    • Avoiding sprays (except flea sprays) in the household.
    • Vacuum and dust regularly.
    • Keep your dog up to date with their flea treatment; symptoms are likely to flare-up if they’re bitten.


  • Skin supplements – help some dogs but not others. They aim to improve skin health. You can buy skin supplements from your vet practice, pet shops and online.
  • Special food may be recommended to keep your dog’s skin as healthy as possible.

When to contact your vet

Make an appointment with your vet if your dog has itchy skin, or any of the symptoms above. Whatever the cause, itchy skin very rarely goes away on its own and is likely to make your dog sore and miserable.

You know your dog best. If they don’t have the symptoms listed above but you are still concerned it’s always best to contact your vet.

Breeds prone to atopy

Breeds most likely to develop atopy include:

  • West Highland White Terrier
  • Bichon Frise
  • Shar Pei
  • Beagle
  • Labrador Retriever.


Treatment for atopy can mount up to thousands of pounds over a dog’s lifetime. Think about insuring your dog as soon as you get them, before any signs of illness start, so you have all the support you need to care for them.

It’s also very important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your dog. There are often several treatment options so if one doesn’t work for you and your pet then your vet may be able to offer another.


Having constantly itchy, sore skin can make a dog very miserable. Dogs with atopy can live a long and happy life if you work closely with your vet to give them the correct treatment.

Your dog is likely to have ‘flare-ups’ from time to time even after they appear to have been controlled with medication. These flare-ups can be quickly resolved by visiting your vet for treatment.

Published: January 2019

PetWise Pet Health Hub – brought to you thanks to support from players of People’s Postcode Lottery 

Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst