Allergy Tests for Cats

Estimated Reading Time 5 minutes
Allergy Tests for Cats

Cats can suffer from allergies, too. Just like humans, your cat may be allergic to various substances called “allergens” that may be present in the air that they breathe, in their food, and in things that they touch or come in contact with. Allergies in cats occur as a result of a hypersensitive reaction to specific allergens. Continue reading to learn more about allergies in cats, including symptoms, causes, and testing options.

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Symptoms of Allergies in Cats

  • The most common signs of allergies in cats include:
  • Sneezing
  • Excessive grooming or licking and scratching
  • Paws that are swollen and sensitive
  • Red or dry skin, ear infections,
  • Itchy runny eyes
  • Vomiting
  • Diarrhea

Types of Allergies in Cats

Allergies in cats are commonly classified into four categories: environmental, food, seasonal, and flea allergies.

1. Environmental Allergies in Cats

The common allergens that have been implicated in environmental allergies (also called atopic dermatitis or atopy) include pollen, dust, mold, grass, and fungi. Some cats may also be allergic to perfume, cigarette smoke, and some household cleaning products.

2. Flea Allergies in Cats

Some cats develop an adverse reaction to flea bites, specifically an allergen substance that is present in the saliva of fleas. Cats with flea allergies suffer from generalized itching even from just a flea bite or two.

3. Food Allergies in Cats

Cats with food allergies have a hypersensitive reaction to something in their diet. Common symptoms of food allergies include vomiting and/or diarrhea, and skin itching.

What to Do if You Think Your Cat Has Allergies

If your cat appears to be exhibiting symptoms of allergies, it’s highly recommended that you schedule an appointment with your vet. Considering that there are several types of allergies in cats, a visit to your vet can help determine the cause of your pet’s issues so the appropriate treatment can be given.

Before your vet starts performing an allergy test, your pet will be examined for fleas to make sure that it’s not a flea allergy. If your cat does have fleas, appropriate flea treatment is given to eliminate the pesky parasites. However, if your pet’s allergic reactions fail to be resolved, your vet may deem it necessary to perform allergy testing.

RAST (Allergy) Testing for Cats

Also called Radioallergosorbent Test, RAST is a blood test that can help determine if your cat is suffering from environmental allergies (inhalant allergies or atopy). The test measures IgE levels which is a type of antibody in the immune system of cats. However, RAST is not efficient in diagnosing food or contact allergies.

A blood sample will be taken by your vet and will be tested for the presence of specific antibodies that may be present in response to different environmental allergens such as pollen, molds, or chemicals. The blood sample will have to be taken to a laboratory and the results may take 1-2 weeks.

The RAST was created for humans, thus it may show a false positive when used in cats. This is one important reason why veterinarians also recommend intradermal skin testing (IDST) when atopy or inhalant allergies are suspected. However, the accuracy of IDST in diagnosing feline allergies is only about 80%.

Intradermal Testing (IDST) in Cats

The intradermal testing (IDST) or skin prick involves injecting very small amounts of different substances (potential allergens) just under the skin of the cat. If the cat is allergic to a certain allergen, there will be a distinct reaction in the skin where the allergen was injected. Your vet will be checking for a localized allergic response that typically includes the formation of a hive, inflammation, or redness. One benefit of the IDST is that results are available immediately.

For this test, a portion of your cat’s hair coat needs to be shaved off for ease of injection and examination of any allergic reaction. The cat should not be given antihistamines and/or steroids before an IDST because these medications can affect the results. Withholding anti-itch medication can be uncomfortable for your pet.

Food Allergy Testing for Cats

When a cat’s allergy is suspected to be caused by an adverse reaction to something in their diet, food allergy testing is recommended. However, food allergies are very difficult and, in some cases, impossible to identify because the cat could be hypersensitive to any of the components of their diet. Food trials may go on for several weeks or months to successfully identify the allergen culprit.

How to Perform a Food Trial for Your Cat

When your cat is on a food trial, she will be given a diet that does not contain any ingredient that is in her regular diet. During the first few weeks, the new diet is composed only of one protein source and one fiber source. If your cat does not manifest any adverse reaction, a new ingredient will be introduced to your pet’s diet during the fourth week. Your cat will be closely monitored for any sign of an allergic reaction. If there’s no reaction, a new ingredient will be added to your pet’s diet every two weeks. If your cat develops an allergic reaction after the addition of a new ingredient, the allergen is now identified.

The food trial, however, doesn’t end once an allergen is detected. Testing will continue because your cat may be allergic to other food allergens. Once the culprit allergens have been identified, your cat will be given a special diet that excludes the allergens.

Read more:

Common Ear Problems in Cats

Ear Mites in Cats

What causes hair loss in cats?

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Published: 8/4/2021
Last updated: 8/5/2021

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