Allergies in Cats: Common Cat Allergy Symptoms and How to Manage Them

Just like humans, cats can have allergies — and their symptoms can be just as irritating as ours. Cat allergy symptoms can range from itchy skin to upset stomachs, depending on the type of allergy. Regardless of whether it’s their food, fleas, or something in the environment, identifying the root cause is key.

How can you tell if your cat has allergies, and what can you do to help them? Let’s dive into the most common cat allergy symptoms, treatment options, and when to see a veterinarian.

Cat allergy symptoms

Allergies in cats can present in different ways. But there are some common symptoms that owners can watch out for.

Excessive scratching, licking, or grooming

Allergies often cause cats to scratch intensely, especially around sensitive areas like their face, neck, and belly. Flea allergy dermatitis, in particular, can lead to obsessive licking or scratching at the site of flea bites.

Hair loss or bald spots

It’s common for cats with allergies to have hair loss or bald spots in their fur, especially where they’ve been frequently licking or scratching.

If your cat has hair loss or is scratching in specific areas, fleas may be the culprit. “In cats, fleas love to be around the neck and base of the tail,” Paige Adams, DVM, a veterinarian in Marietta, Georgia, told GoodRx.

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Skin redness, bumps, or sores

Flea allergies or contact dermatitis can cause visible redness or irritation on your cat’s skin. This can include flaky patches, bumps, and open sores.

Chronic ear infections or head shaking

Ear infections are another common symptom in cats with allergies. This can lead to head shaking from discomfort.

Watery eyes or nasal discharge

Just as we do, cats can experience watery eyes and nasal discharge from environmental or seasonal allergies from pollen or dust.

Sneezing or coughing

Respiratory issues, like sneezing and coughing, are also common with environmental allergies. These symptoms are easy to mistake for an upper respiratory infection. It’s important to keep an eye on any patterns or triggers that lead to upper respiratory symptoms.

Vomiting or diarrhea

If your cat has a food allergy, they might show digestive symptoms like vomiting or diarrhea. This is more common in cats who are allergic to certain proteins or ingredients in their food, like chicken or beef. But food allergies are rare in cats (and dogs).

What causes allergies in cats?

Allergies in cats are caused by an overactive immune response to certain allergens. These allergens are typically harmless for most cats, said Eliza O’Callahan, DVM, the managing veterinarian at Small Door Veterinary.

The four common causes of allergies in cats include:

• Flea allergy dermatitis: An allergic reaction to flea saliva, often causing intense scratching and skin inflammation

• Environmental allergies: Reactions to airborne allergens like pollen, mold, or dust mites, similar to hay fever in humans

• Food allergies: Sensitivity to certain proteins or ingredients in their diet, such as chicken, beef, or dairy

• Contact allergies: Reactions to materials or substances they come into physical contact with, such as detergents, certain plastics, or perfumes

Some cats have a genetic predisposition to developing allergies. Pure-bred cats have a higher chance of having allergies than the average mixed-breed cat.

When should you see a vet about cat allergy symptoms?

Visit your veterinarian if your cat shows allergy symptoms, especially if they’re persistent or getting worse.

Some telltale signs it’s time to make a vet appointment are if your cat:

• Is excessively scratching, licking, or grooming

• Develops hair loss, sores, or redness on the skin

• Has chronic ear infections or unusual head shaking

• Experiences sneezing, coughing, or respiratory symptoms

• Shows gastrointestinal symptoms, like vomiting or diarrhea

Early diagnosis and treatment are key to managing allergies and preventing infections or complications.

“I recommend people don’t wait until there’s wounds or a skin infection,” Adams said. “[Otherwise] treatment will be more extensive and stressful for both the cat and owner.”

How do you diagnose cat allergies?

Diagnosing cat allergies can be a bit tricky. It often involves a process of elimination to rule out other causes of similar symptoms, like infections or parasites.

According to O’Callahan, the key steps to diagnose allergies include:

• Reviewing your cat’s symptoms

• Reviewing their diet history

• Asking about their environment

• Certain allergen tests or trials

“Keeping up with strict flea prevention, introducing a hypoallergenic diet, and doing blood or skin testing can all help in identifying the type of allergy we’re dealing with,” O’Callahan said.

Adams added that seasonality can offer clues. “If symptoms only appear at certain times of the year, we may suspect environmental or seasonal allergies,” she said. In some cases, seeing a veterinary dermatologist for further testing might be necessary to pinpoint specific allergens.

How do you treat allergies in cats?

Treatment for allergies in cats depends on the underlying cause.

Flea allergies

Flea allergies are typically managed with year-round flea control. These products are applied monthly to your cat’s skin or given as a pill. Common flea medications for cats include:

• Comfortis (spinosad)

• Credelio (lotilaner)

• Capstar (nitenpyram)

• Bravecto (fluralaner)

• Revolution (selamectin) 

• Advantage Multi (imidacloprid and moxidectin)

Food allergies

Food allergies, on the other hand, may require a hydrolyzed or prescription diet. The goal is to eliminate the ingredients your cat is allergic to from their diet.

A hydrolyzed diet takes regular cat-food ingredients and processes them in a way so that a cat’s immune system can’t recognize them. As a result, the immune system doesn’t cause an allergic reaction to the food.

Other prescription diets focus on feeding your cat new proteins that they likely haven’t eaten before. Common options include rabbit or venison. Because these are new ingredients, your cat is less likely to be allergic to them.

Environmental allergies

“Cats with environmental allergies are usually given [medications],” O’Callahan said. These are often used for long-term management. Common options for cats include:

• Antihistamines

• Steroids such as prednisolone

• Allergen-specific immunotherapy, like allergy shots or drops

Adams said that there are fewer medications available for managing symptoms in cats compared with dogs. But for cats, steroids like Atopica (cyclosporine) remain a primary treatment for severe allergy flares.

“In some cases, a combination of medications might be necessary,” she added.

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Written by:

Emily Johnson

Emily Johnson is a content writer specializing in the pet industry, with expertise covering pet health and nutrition, pet insurance, dog training, and everyday living as a pet owner. Before freelancing, she was the content manager for a pet company and has worked closely with veterinarians, nutritionists, pet insurance companies, and other pet experts.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

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