Pet Allergy Testing for Dogs and Cats: A Guide for Owners
Allergy testing in dogs and cats helps identify environmental triggers behind ongoing skin problems, allowing vets to create a targeted treatment plan.
Does my pet need an allergy test?
If you’re worried that your cat or dog may be suffering from an allergy, it’s a good idea to visit your vet to discuss diagnosis and treatment options. Common allergy signs in pets include:
Excessive itching and scratching of the skin
Skin rashes (especially on the feet, ears, bottom, belly, and face)
Patches of fur loss
Licking or biting a particular area for long periods (saliva can cause brown staining on the fur)
Itchy eyes
Runny nose
Mood changes
Scabby or sore skin
What is pet allergy testing used for?
Pet allergy testing is most commonly used in animals diagnosed with atopic dermatitis, a chronic allergic skin condition usually caused by environmental allergens such as pollens, grasses, dust mites, and mould spores. It is not usually the first step in investigating itchy skin, but it is used once other common causes have been ruled out. The main purpose of testing is to identify which allergens are triggering symptoms, so that targeted treatment (allergen-specific immunotherapy) can be designed. Allergy testing is less reliable for diagnosing food allergies, and a food elimination trial is usually required for this.
Why is immunotherapy used for pet allergies?
For pets with atopic dermatitis, allergy testing is often carried out to support allergen-specific immunotherapy. Immunotherapy works by gradually desensitising your pet’s immune system to the environmental allergens that trigger their symptoms.
Treatment involves giving regular injections of very small amounts of the identified allergens. Over time, this can reduce the severity of allergic reactions and, in some cases, decrease the need for long-term medication. Immunotherapy is the only treatment approach that aims to modify the underlying allergic response rather than simply controlling symptoms.
Immunotherapy is a long-term treatment, and improvement is usually gradual, often taking 6–12 months to become noticeable. During this time, many pets will still need medication to help manage symptoms. Not all pets are suitable candidates, and your vet will discuss whether immunotherapy is appropriate based on your pet’s diagnosis, test results, and overall health.
Clinical studies suggest that approximately 50-75% of pets respond favourably to immunotherapy. Costs for immunotherapy vary depending on the number of allergens involved. Your vet will always discuss costs in advance, so you can make an informed decision about your pet’s care.
How does a pet allergy test work?
Serological (blood) testing
This involves testing the blood, looking for allergen–specific antibodies (IgE) which react to several common allergens, which may be contributing to atopic dermatitis. This is a convenient, simple pet allergy test that can be helpful in some cases, but intradermal testing is typically preferred by veterinary dermatologists when available.
Intradermal skin testing (IDST)
This is the most used method by veterinary dermatologists when investigating environmental allergies. The test involves clipping the hair on the side of your pet’s chest and giving multiple small allergen injections into the skin. If your pet reacts to an allergen, a hive will develop at the injection site. Pets will usually need to be sedated for intradermal skin testing.
How to help pets with allergies
Managing allergies usually involves a combination of identifying triggers and controlling symptoms. Your vet will tailor a plan to your pet, which may include several of the following:
Regular treatment with a parasite control medicine
Conducting a food elimination diet trial (this will involve feeding your pet an alternative diet which cuts out certain allergens. Then, after the dietary exclusion period, you’ll start reintroducing ‘normal’ foods to see which (if any) foods trigger allergic reactions in your pet).
Allergy testing
Avoidance (where possible) of allergens – such as plants or chemicals
Treatment – e.g., immunotherapy or medication to control symptoms
Please note that while simply avoiding known allergens may help to reduce symptoms, it’s often unlikely to completely resolve them. Therefore, an additional form of treatment (e.g. medication) is usually required.
How much does a pet allergy test cost?
Some pet allergy cases may need to be referred to a specialist dermatologist for an intradermal skin test. The costs for this are typically higher and usually require a consultation before testing. Costs will vary depending on whether sedation is required.
Does pet insurance cover cat and dog allergy testing?
Pet insurance may help to pay for allergy testing if it’s recommended by your vet as the best treatment (for example if your pet is suffering from itchy skin). However, all policies vary in what they cover and what exclusions are in place. We recommend checking your policy and speaking with your insurance company to check you are covered before proceeding with the tests.
Written by Gill Burkhill, Veterinary Surgeon, Animal Trust Vets CIC | Published March 2026 | Review date March 2029 | This advice is for UK pets only and is not a replacement for seeing a vet
