Allergies and pets

Allergies and pets

There’s no getting around it – hayfever is the worst! As it moves into spring, pollen starts flying and noses start running and these seasonal allergies can also affect our cats and dogs! Here we’ve put together some information to help you identify if your pet is just having a good scratch, or if it’s a sign of an underlying allergy, as well as what you can do to minimise your pet’s discomfort and prevent the reaction from worsening.

What are allergies and pets?

Allergies are hypersensitivities in the immune system to a particular allergen. Just like people, pets can be allergic to many different things – food, things from the environment like pollen or fabric and insects such as fleas. Their immune system overreacts to the antigen, causing inflammation and swelling, which can be painful or even life-threatening for your pet. Most pets develop allergies between 9 months and 4 years.

The characteristic sign that your pet has allergies is excessive scratching, but different allergic reactions can be associated with different symptoms:

Allergen Symptoms

Some pets react strongly to flea saliva, and when bitten can develop
flea allergy dermatitis (FAD)

Severe local itching at the flea bite site

Hair loss at the bite site (from scratching) particularly at the tail base

Environmental allergens (atopy)

This is similar to hayfever in humans, and occurs when a pet is allergic to pollen,
dust mites or moulds from the environment

Itchy skin, particularly at the armpits, groin or between the toes

Runny discharge from the nose or eyes

Sneezing or coughing


Food allergies are less common than FAD or atopy.
They occur if a pet is allergic to a protein or ingredient in their food.

Itchy skin and scratching

Gastrointestinal side effects such as vomiting or diarrhoea

Contact allergies

Reactions caused by contact with a substance, usually a plant

Localised redness or itching at the contact site (usually at the feet or stomach)

Things you can look out for that may suggest your pet has an allergy include:

  • Chewing, licking or biting their feet or tail
  • Redness and scratching at their belly, armpits or groin
  • Rubbing their ears or face

Diagnosing allergies:

Since the symptoms of allergies can be very similar, the exact cause must be carefully investigated to minimise future exposure to your pet. Contact and atopic allergies can often be diagnosed via a blood test. FAD only occurs if your pet has been bitten by fleas. Food allergies can be harder to diagnose. If your pet’s symptoms improve if they follow a diet of a protein they have not eaten before, then it is likely they have a food allergy. After this, you can slowly introduce new foods (alongside the guidance of your vet) to identify which food is the cause.

Treating allergies is extremely important for your pet’s wellbeing, as constant itchiness is not only extremely uncomfortable, but can also lead to secondary infections if the skin is broken. Luckily, there are a range of things you can do to ease the symptoms of allergies and make life more comfortable for your pet.


Prevention is the best treatment for FAD. Ensuring that your pet is using an anti-flea medication can prevent the allergic reaction from developing in the first place. If your pet already has FAD, topical steroids or oral antihistamines can be used to relieve symptoms, as well as anti-flea shampoos to kill any fleas still left on your pet. Your veterinarian can advise you on the best treatment options for your pet.

Atopic dermatitis

These allergies require long-term management. Firstly, eliminate the allergen from your pet’s environment as much as possible. Bathing using a hypoallergenic shampoo helps by soothing inflamed skin as well as washing the allergen out of your pet’s coat. Be sure to use a specialised pet shampoo to protect the natural oils in your pet’s coat. Focus on washing areas that cause your pet the most discomfort, such as their armpits and in between their toes.

If symptoms do not improve, discuss options with your veterinarian such as anti-inflammatory therapy with steroids or antihistamines. Desensitisation therapy is also an option if the allergen is identified. Your pet is given repeated low-dose injections of the offending allergen, and over time their immune system becomes more tolerant of it, reducing the severity of their reactions.

Food allergies and pets

 If you know the allergen that is causing your pet’s reaction, then you can simply eliminate them from their diet to prevent symptoms. There are specialised foods available for pets which contain only hydrolysed proteins. In these foods the proteins are broken down into very small pieces and are less likely to elicit a reaction.

Contact allergies

For identified allergens, minimise your pet’s exposure, for example, by removing allergenic plants from your garden. When walking your dog, keep them away from dense undergrowth where they may come into contact with any allergens, and take care to pick out any burrs or seeds that may get trapped in their ears, coat or toes. If your pet is having a reaction, topical creams can provide relief, and antibiotics can be used to treat ear infections or infections in areas of broken skin.

  • Despite the popularity of ‘grain-free’ pet foods, the most common food allergens in pets are animal proteins such as chicken or beef
  • Just like people can be allergic to pet allergens such as fur or dander, animals can also be allergic to human allergens!
  • Seasonal allergies can cause your pet to snore at night as their airways become congested
  • Food allergies account for only 10% of pet allergies