Allergies in Cats: How to Spot, Treat, and Prevent Them


Allergies in Cats: How to Spot, Treat, and Prevent Them

Itchy kitty? Allergies could be to blame—and relief might be a visit to the vet or a swap of the litter away. janelle leeson
janelle leeson By Janelle Leeson August 11, 2022 Advertisement Pin FB More Tweet Email Send Text Message Print cat scratching his ear; allergies in cats
cat scratching his ear; allergies in cats Credit: chendongshan / Adobe Stock

On This Page

  • Can Cats Have Allergies?
  • Causes
  • Types
  • Symptoms
  • Testing
  • Treatment

We humans know allergies are no fun. But what about our furry friends? Can a cat have allergies—even indoor ones? They sure can, says Brian Evans, DVM, from Dutch. And feline allergies can disrupt your cat's daily life as much as human allergies disrupt ours. Allergies in cats can wreak havoc on everything from the upper respiratory system to the skin and the GI tract.

You might feel hazy when it comes to discerning feline allergies from other conditions, like a kitty cold or asthma. But with the right tools, you can spot the signs of an allergy attack and work with your vet to find your cat relief. Some allergies may even resolve with a few simple tweaks at home.

Can Cats Have Allergies?

Yes, and some types of allergic reactions in cats are more common than you might think. Whether your cat is an indoor or outdoor cat, Evans says there's a wide spectrum of allergens and your cat is likely to come in contact with at least one type. Plus, a cat's exposure to allergens can increase if they share their home with a dog or two.

RELATED: Are There Hypoallergenic Cats? Scientists Are Getting Closer to Making That a Reality

Causes of Allergies in Cats

As the College of Veterinary Medicine at The Ohio State University says, "an allergy is a reaction that occurs when the body's natural defenses overreact to a foreign substance called an allergen." When the body (cat, human, or dog) is exposed to a substance it registers as bad, the immune system kicks into high gear to release histamines—way too many histamines.

Histamines are naturally occurring chemicals in your body, but too many of them can cause your cat discomfort in the form of inflammation, itchiness, and swelling. Both male and female cats of all ages and breeds can develop an allergy throughout their lives, and some cats may be born with a genetic predisposition to react to allergens.

Types of Allergies in Cats

You can think of allergies in cats as three different types: environmental, flea, and food allergies.

Environmental Allergies

Environmental allergens are found indoors and outdoors. Indoor irritants like fragrances, mold, and dust can trigger an allergic reaction in us and our feline friends. Outdoor seasonal allergens like pollen, grass, and insects can also trigger a reaction. Cats can even be allergic to human dander, Evans adds.

Flea Allergies

Cats (and many humans) have an allergic reaction to the bites of fleas and their saliva. Flea allergies are the most common type of allergy in cats. Lucky for us and our cats, it's also one of the easiest to prevent thanks to monthly flea preventatives.

Food Allergies

Allergic reactions to foods are fairly uncommon in cats. Your cat might have digestive upset from certain ingredients in their food like corn, carbohydrates, and gluten, but a reaction to the GI tract only is called a food sensitivity, not an allergic reaction. When your cat eats something that triggers a reaction to the immune system—like itchy skin that may or may not be accompanied by GI upset—that's an allergic reaction. A food allergy is "typically caused by a reaction to the protein source of the food like beef or chicken," Evans says.

RELATED: Cat Skin Conditions: How to Recognize & Treat Ear Mites, Ringworm, Fleas, and More

Signs and Symptoms of Allergies in Cats

No matter the allergen, Evans says that allergic reactions in cats can share a lot of the same symptoms. Symptoms of allergies in cats include:

  • Red, irritated skin (in one part of the body or generalized)
  • Scabbing of the skin
  • Itchiness or rashes
  • Rubbing of the face
  • Hair loss (localized or generalized)
  • Chewing, biting, or licking at the paws
  • Hives
  • Swelling, including facial features like the lip
  • Sneezing
  • Chronic cough
  • Runny eyes
  • Diarrhea
  • Vomiting

Wondering how to know if your cat has a cold or allergies? Unlike a kitty cold, "cats with allergies tend to have skin issues whereas upper respiratory infections stay within the nose and eyes," Evans says. When it comes to asthma, differentiating between an allergy attack and an asthma attack can be tricky. That's because some forms of asthma can be triggered by an allergen, but the hallmark of an asthma attack is difficulty exhaling accompanied by wheezing sounds.

The bottom line, if your cat is displaying any unusual behavior or signs, she should see her vet for a check-up.

Testing Your Cat for Allergies

There are a few types of allergy tests your vet can perform when attacks are severe or eliminating the allergen isn't providing relief.

Blood Testing

Like blood tests for allergies in dogs and humans, your vet can take a small vile of blood to test for allergies. This is the most non-invasive method of allergy testing, but it can take one to two weeks for results. In addition, allergy blood tests are less reliable than skin allergy testing.

Intradermal Skin Test

Skin testing for allergies is the most reliable method, but it's also the most invasive. For this method of testing, your vet will sedate your cat and inject small amounts of allergens into your cat's skin. Your vet will likely need to shave a portion of fur to see any skin reactions, but the results are immediate and vast (with the exception of food allergies). Some vet offices and feline dermatologists may advise on an allergy treatment the same day.

Flea Allergy Testing

Your cat likely is brushed for fleas and flea dirt at her routine vet visits. If your vet finds evidence of fleas and your cat is itchy or has irritated skin, your vet will recommend a monthly flea medicine—a preventive staple for cats with or without flea allergies.

Food Allergy Testing

"Unfortunately, there is not a good test for food allergies," Evans explains. "The only "test" for a food allergy is by going through a strict elimination diet trial." Because elimination diets can be long and sometimes frustrating, it's best to work alongside your vet.

RELATED: Top Tips for Getting the Most Out of Your Vet Visit

How to Treat Allergies in Cats

Treatment of allergies can be as simple as starting a monthly preventative treatment for fleas—which can also protect your cat from other parasites like ticks and heartworms. Vacuuming more often, using a HEPA air purifier, and wiping your cat off after every outdoor adventure can curb allergy attacks, too. Lastly, swap out dusty litter for low dust, non-scented litter, and make sure your cleaning products are pet-friendly.

When at-home changes aren't providing your cat with relief, ask your vet which over-the-counter antihistamine medications are safe.

If your vet or feline dermatologist has completed an allergy test on your cat, then immunotherapy might be an option. This approach uses the results from your cat's allergy test to create a serum tailored to your kitty. This serum contains small amounts of specific allergens. When successful, injections of the serum desensitize your cat to the allergens over time.

When it comes to food allergies, your vet can prescribe medications that provide relief to the symptoms of the allergy. But the best approach is to work with your vet to remove the problematic protein and stick with limited-ingredient foods or a prescription diet.

Allergies in cats can feel as frustrating for us as they do for your itchy cat. But with your vet's help and some patience, you can find a treatment and management plan to keep your cat comfortable and symptom-free.

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