Skin allergies in dogs

photo of dog on white background


  • Allergic skin disease (skin allergies/atopic dermatitis) is an extremely common cause of red, itchy skin in dogs.
  • Skin allergies are triggered by things your dog encounters in their daily life, such as fleabites, food or pollens.
  • Symptoms include red, itchy skin, infections and hair loss.
  • Treatment depends on what your dog is allergic to, but often focuses on strict flea control, avoiding allergic triggers, a special diet, and medication to stop the itch.
  • Contact your vet if your dog has symptoms of a skin allergy.

General information

A skin allergy (also called allergic skin disease or atopic dermatitis) is an allergic reaction that develops when a dog is sensitive to something they encounter in their daily life. There are three common types of skin allergy that link to the main allergic triggers: fleabites, food, and things in the environment (such as pollen, grasses and trees). Most dogs with allergic skin disease have more than one trigger and this can make skin allergies a complicated disease to manage

Skin allergies can develop at any age and in any breed of dog, but are most common in certain breeds such as the West Highland White Terrier, Bichon Frise and Shar Pei.

Types of skin allergy

The three most common skin allergies are:

Flea allergy

If your dog is allergic to fleabites, they will have an exaggerated reaction every time they are bitten, similar to a person allergic to mosquitoes. Even one fleabite can cause intense itching that lasts for a long time. If your dog has a flea allergy, they are likely to develop a rash, scabs and hair loss around their inner thighs and lower back.

Food allergy

If your dog is allergic to something in their food, they are likely to develop skin problems and tummy upsets. Red, itchy skin, soft stools, diarrhoea and wind (farts) are all common symptoms of a food allergy. Symptoms can develop at any stage but are most common before a year old. Food allergy symptoms tend to come and go over time, and are likely to be much worse if your dog’s eats something different to their usual diet.

Environmental allergies

If your dog has an allergy to something in the environment, such as pollen, trees, dust mites or grass, he/she is likely to develop itchy skin at certain times of the year. Symptoms are often worse during spring and summer, similar to humans with hay fever.

Many dogs with skin allergies are allergic to more than one of the above.


Symptoms of allergic skin disease can affect any area of skin but most commonly affect the ears, paws and belly. Common symptoms include:

If your dog is allergic to something in their food, they may also suffer with mild tummy problems such as soft stools, diarrhoea and/or wind (farting).

Photo of a dog with atopy

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

When to contact your vet

It's important to contact your vet ASAP if your dog has a skin problem because left untreated, skin allergies can have a serious effect on your dog's health and quality of life.


Most dogs with allergic skin disease have more than one trigger, but without running many different tests, it can be very difficult to find out the exact cause. Blood and skin tests are available, but unfortunately, they don’t always give accurate results. Fortunately, it’s not always necessary to find out what each dog is allergic to because many types of skin allergy are treated in the same way.

Often, before any tests, your vet will ask you to rule out fleas by treating your pets and household, and conduct a ‘food trial’. If your dog is still showing symptoms of a skin allergy once both of these have been ruled out, they are likely to be allergic to something in the environment, such as pollen, trees, moulds or dust mites.

Treatment and ongoing care

There is no cure for allergic skin disease but most dogs can be well managed with treatment from your vet. Treatment is likely to include the following:

Avoiding triggers

The ideal treatment for allergic skin disease is to avoid what your dog is allergic to so that symptoms don’t develop in the first place. It’s often impossible to completely avoid what your dog is allergic to, but limiting their exposure is likely to help.

If your dog is allergic to something in the environment, you can:

  • Avoid walks when the pollen count is high and try to stick to pavements.
  • Rinse your dog’s coat after a walk in grass, especially their feet and belly.
  • Avoid sprays (except flea sprays) in the household.
  • Vacuum and dust regularly.

If your dog is allergic to fleabites, you can:

  • Keep your dog (and all other pets) up to date with their flea treatment. Remember to treat your house as well.

If your dog is allergic to something in their food, you can:

  • Feed them a special food recommended by your vet.
  • Avoid any treats other than those recommended by your vet.


  • Steroids and other ‘anti-itch’ tablets can be used to calm your dog’s skin and reduce the itch.
  • Steroid skin spray can be used alongside tablets to calm particularly itchy areas of skin.
  • Antibiotics may be needed if your dog has a skin infection, and eardrops may be necessary if your dog’s ears are sore.


If you have found out what your dog’s allergies are through testing, tailored injections (also called immunotherapy) can be made to reduce the reaction they have. The injections work slowly over time and may need to be given regularly for the rest of your dog’s life. Immunotherapy doesn’t work for every dog and medication is often still needed to reduce symptoms or flare ups.

Skin supplements

Skin supplements aim to improve skin health and help some (but not all) dogs. You can buy skin supplements from your vet practice, pet shops and online.


Although there is no cure for a skin allergy, with the right treatment, your dog will be able to live a long, happy, itch-free life. They might have ‘flare-ups’ from time to time, but these can usually be quickly resolved with some additional treatment from your vet.


Lifetime treatment costs for allergic skin disease can mount up to thousands of pounds so it’s 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 is often more than one treatment option, so if one doesn’t work for you and your pet then your vet may be able to offer another.

Consider 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.

Published: August 2020

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

Illustrations by Samantha Elmhurst