Is My Cat Allergic To Fleas?

When a flea bite goes from bad to worse 😖

itchy cat

Your cat is itching like crazy, so of course you’re wondering what the deal is.

One possible explanation is flea allergy dermatitis, which means she has an allergy to fleas — so imagine the itchiness of fleas, multiplied by an allergic reaction!

The Dodo reached out to Dr. Ursula Oberkirchner, a veterinary dermatologist and owner of Advanced Veterinary Dermatology in Florida, to find out what flea allergy dermatitis is and how it can affect your cat.

What is flea allergy dermatitis in cats?


If your cat has flea allergy dermatitis, it means she’s allergic to flea bites.

According to Dr. Oberkirchner, it only takes one or a few flea bites to cause an allergic reaction in your cat. When this happens, she will become severely itchy — even itchier than she’d be with just fleas alone — which can get worse over time.

“Cats who suffer from FAD typically are severely itchy and often require veterinary care to help them become and stay comfortable,” Dr. Oberkirchner told The Dodo.

Even if you don’t see fleas or flea dirt on your cat or in your home, and your other pets seem totally fine, it’s possible your cat still has a flea allergy — since it only takes one bite to cause a reaction.

“It is important to know that FAD is not the same as a flea infestation,” Dr. Oberkirchner said. “In FAD, it is often a single animal that is affected and, typically, the owners have never seen fleas on their pet(s) or in their environment.”

Flea allergy dermatitis symptoms


If your cat has flea allergy dermatitis, she might show the following signs:

  • Inflamed skin
  • Bald spots
  • Increased licking, scratching and chewing on the skin

While a dog with flea allergies might itch in specific areas (like around the tail) “cats, on the other hand, may itch anywhere on their body and often develop crusty papules [aka raised areas of skin tissue],” Dr. Oberkirchner said.

If your cat is showing any of these signs, you should take her to the vet immediately.

How to soothe flea allergy dermatitis in cats


If your cat is having an allergic reaction to fleas, your veterinarian can help give your cat relief.

Your vet might prescribe medication like Atopica, which is an immune-modulating pill that targets inflammation, or a round of steroids, which are more potent and typically only used for severe cases.

There are some over-the-counter (OTC) medications, like antihistamines, that might help, but they won’t be as effective as prescription medications. So they’re not a substitute for a vet visit, but they may help, for example, if you can’t get an appointment until the next day and you’re looking for some overnight relief.

When buying antihistamines for your cat, make sure they don’t contain decongestants or alcohol, which can be dangerous for her.

Try this cat-friendly antihistamine from Amazon for $4.25

Antihistamines should also be taken with an omega-3 fatty acid supplement to give your cat additional relief.

Try this Zesty Paws Wild Alaskan salmon oil from Amazon for $14.97

An anti-itch spray can also reduce scratching.

Try this medicated shampoo from Amazon for $8.58

How to prevent flea allergy dermatitis symptoms


The best way to prevent flea allergy dermatitis in cats is by administering a reliable monthly flea and tick medication to each of your pets.

“To help prevent symptoms of FAD from occurring in the first place, it is crucial to use excellent and continuous flea prevention for all animals in the household,” Dr. Oberkirchner said.

Try Advantage II for cats from Amazon for $58.98

Or try Cheristin for cats from Amazon for $69.99

Or try Comfortis prescription medication for cats from Chewy for $101.99

If you suspect your cat is allergic to fleas, don’t stress. She’ll be healthy in no time with a vet visit, a few products and a reliable monthly flea medication.

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