Everything Pet Parents Needs To Know About Allergies In Cats

If your cat has allergies, she’s probably doing a lot of itching.

This can be super frustrating to watch, and your poor cat probably hates it even more, so you definitely want to get her relief ASAP.

If your cat has allergies, she could be allergic to fleas, food or something in her environment — and after your vet diagnoses the allergy trigger, they might prescribe allergy shots, medication or topical treatments to help her feel better.

The Dodo reached out to Dr. Ruth Lee, a veterinarian at Veterinary Care Group Forest Hills in New York City, and Dr. Sarah Wooten, a small animal veterinarian in Colorado, to find out everything pet parents need to know about cat allergies.

Like humans and dogs, cats can have allergies, too.

Cats can be allergic to things in their environment, fleas and food. These categories include potential allergens like medications, perfume, fabric, insects, plastic, grass and even humans!

If your cat has an environmental allergy, she’s allergic to something in her surroundings, like dust, smoke or cleaning products.

Sometimes, your cat is allergic to something that comes around seasonally, like pollen. If your cat only has reactions in the spring, for example, this is a good indication that your cat has seasonal allergies.

If your cat has a genetic disorder called atopic dermatitis, this will definitely make her environmental allergies a lot worse. (A vet can help you determine if your cat has atopic dermatitis.)

If your cat’s environmental allergies are mild, your vet might recommend medication, but in severe cases, they might recommend allergy shots (aka immunotherapy) that could essentially cure your cat of her allergy — but more on that below.

Cats can also be allergic to flea bites.

When a cat’s allergic to fleas, it only takes one bite to cause a reaction. And instead of creating a mild itching sensation near the bite site, a flea allergy means that flea bite is making your cat itch all over and triggering all the typical cat allergy symptoms (more on that below).

And since cats are expert groomers, you might not see a single flea on your cat even though she’s having a reaction.

The best solution for this is to always keep your cat on a reliable cat flea preventative if she isn’t already.

“If a cat has an allergy to flea bites, then the best thing to do is regularly keep your cat and all other dogs and cats in the household on veterinarian-recommended flea products,” Dr. Wooten told The Dodo.

Cats can also be allergic to something in their food. The most common cat food allergens are beef, fish and milk and other dairy products.

“Corn and wheat allergies are much less common,” Dr. Wooten said.

To diagnose a food allergy in cats, your vet might run a food-elimination trial, where your cat is fed a hypoallergenic or novel protein food (which won’t cause an allergic reaction) for a while, and then reintroduced to her old food. If she has a reaction to eating her old food again, then you have a confirmed food allergy.

If your cat has an allergy (no matter to what), she might have the following symptoms:

Most of these symptoms will be present no matter what your cat is allergic to, and sometimes cat allergy symptoms can even resemble symptoms of other health issues.

To diagnose cat allergies, it takes “several steps and various tests,” Dr. Lee told The Dodo. “Patience is the key to coming to a full conclusion.”

It’s important to rule out other conditions that can look like allergies, as well as find out what exactly your cat is allergic to, Dr. Lee said.

To diagnose allergies, your veterinarian might first do a full workup, “which usually starts with skin testing [and] parasite treatments to rule out parasites,” Dr. Lee said. “It may be followed by a strict six- to eight-week prescription hypoallergenic food trial.”

If your vet suspects environmental allergens are the cause, they might recommend skin or blood testing to find out the exact trigger. But since environmental allergies are pretty much unavoidable, a vet would only recommend this type of testing if you’re interested in getting allergy shots (more on that later) to treat your cat’s allergies.

“Typically, allergy testing itself and simply knowing what the patient is reacting to is not helpful, since most of these things are airborne and can travel miles — so the main reason to do this is to develop a recipe for that individual for immunotherapy (allergy shots),” Dr. Lydia Harbour, a veterinary dermatology resident at Dermatology for Animals in Arizona, told The Dodo.

To treat your cat’s allergies, the best thing to do is remove the allergen altogether.

So, if your cat has a flea allergy, that means giving her a reliable monthly flea preventative. For food allergies, the best solution is to identify the allergen and remove it from her diet. Environmental allergies are a bit more tricky, since they can be basically unavoidable (like pollen in the air).

To reduce symptoms from environmental allergies, vets might recommend a prescription medication or an over-the-counter (OTC) medicine. There’s also an immunotherapy treatment available, which actually changes how your cat’s immune system responds to allergens.

Cat allergy medication, either OTC or prescription (depending on how bad your cat’s symptoms are), might be recommended by your vet to help reduce some of your cat’s symptoms.

If your cat has mild allergy symptoms, your vet might recommend a cat-safe antihistamine.

“There are some over-the-counter antihistamines that owners can try for mild signs,” Dr. Lee said. “The most common antihistamine used for cats is chlorpheniramine.”

Try chlorpheniramine tablets for cats from Amazon for $3.89

“However, antihistamines, in general, are considered low-efficacy when it comes to the management of allergies, which is why vets usually only reach for them for mild symptoms,” Dr. Lee said.

For prescription medication, Atopica is a popular option for reducing a cat’s allergy symptoms.

Try Atopica from Chewy for $46.49

Your vet might also prescribe steroids, but only for severe cases. “Veterinarians try to stay away from long-term steroids or use steroids only for severe cases due to side effects, especially in cats!” Dr. Lee said.

Vets can also use immunotherapy (aka allergy shots) to actually treat a cat’s allergies instead of masking the symptoms.

Allergy shots are mostly used for environmental allergies, but there is some limited research on using immunology for food or insect allergies in severe cases.To undergo immunology, your pet needs to have skin or blood tests done to determine the allergen that causes a reaction in your cat. Then, a serum is created with that allergen, which is injected into your pet over time to desensitize your cat to the allergen.

So, the next time your cat is exposed to that allergen, your cat’s immune response won’t be so strong and your cat’s reaction won’t be so bad.

Cat allergy shots are only around 70 to 80 percent effective, though, so they won’t work for every cat. But they’re definitely still a good solution to try if cat allergy medicines aren’t working or you’re looking for a more permanent solution.

Keep in mind that it’s possible your cat will need to receive shots over the course of her lifetime if they work on her, but it still might be a more cost-effective solution than cat allergy medications.

For more information on immunology for cats, speak to your veterinarian, who can give your cat a personalized recommendation.

Allergies can be frustrating for you and your cat, but luckily a treatment plan from your vet can effectively reduce allergy symptoms for a happy and healthy cat.

We independently pick all the products we recommend because we love them and think you will too. If you buy a product from a link on our site, we may earn a commission.