Written by Dr. Cariann Turbeville

Allergies in cats are a common problem. Many allergies are caused by environmental factors such as pollen, dust, or grass. Other allergies may be caused by food or contact with certain materials. Symptoms of allergies in cats can include itching, scratching, pawing at the face, runny eyes, and sneezing. In severe cases, allergies can cause problems with the skin, gastrointestinal system, and respiratory system. Treatment for allergies in cats will vary depending on the cause of the allergies. If you think your cat may have allergies, talk to Airvet about the symptoms your cat is experiencing, testing and treatment options.

What exactly is an allergy?

An allergy is a hypersensitivity to a substance, ranging from pollen to food to chemicals and more. An allergy is considered an abnormal physical reaction involving the immune system’s response to that substance.

Allergies may be inherited, acquired, or both, and many cats experience an allergic reaction at some point in their lives. Allergies cannot be cured, but usually can be managed well enough to provide a comfortable quality of life for your pet. In the best case scenarios, allergic symptoms may be suppressed for long periods of time.

Are allergies in cats dangerous?

The allergies experienced by cats are rarely deadly. However, some of the most potentially dangerous allergies may arise from medication given to your cat. So always monitor your cat closely when she’s taking a new prescription.

To complicate things further, allergic responses can overlap; and may not seem to correlate to the origin of the problem. For example, a food allergy may trigger problems in the skin as well as in the digestive system.

Chronic allergies, such as an allergy to pollen, can reduce your cat’s quality of life.  And they can be a gateway into other physical problems. Pollen allergies can be expressed in the respiratory system, digestive system, skin, or all three.

What are the most common cat allergies?

Skin allergies, also known as allergic dermatitis, is the most common allergy in cats. The three basic causes are allergies to fleas, food, or environmental particles. If symptoms are seasonal rather than year-round, it is likely that something in the environment, such as pollen, is contributing to the problem. Skin allergies in particular pose the risk of secondary infection. As your cat scratches and licks to soothe an itch, they can cause an infection. With this in mind, take care not to let possible signs of an allergy go untreated.

Cats with flea allergy dermatitis (FAD)

Flea allergy dermatitis is an allergic reaction to flea bites, most often to the saliva of the biting fleas. If you notice your cat scratching or licking frantically, especially around its neck or at the base of the tail, consider that your cat may have a flea-related issue. If left untreated, most cats with FAD lose hair at the tail base and down the rear legs, which sometimes is called “flea pants”.

Virtually every mammal on earth serves as host to a flea or two in the course of a lifetime. For cats with no particular sensitivity, an occasional brush with fleas is irritating, but not especially troublesome. However, for a feline with FAD, just one bite can set off a frenzy of extreme itching.

Cats with food allergies

The term “food allergies” may be used casually (and incorrectly) by people who have cats with food sensitivity. The difference is that a sensitivity does not trigger a response from the immune system, but may produce the common symptoms of indigestion and gastric distress. A cat with a true allergy to a food ingredient (most often a meat protein) may develop GI symptoms as well as itching and inflamed skin.

Cats with environmental allergies

Environmental allergies are the equivalent of hay fever in humans. Direct contact with an allergen, whether inhaled, swallowed or introduced via the skin, triggers the response. This is called atopy, a general term for your pet having a predisposition to overreacting to an ordinary allergen.

Other common allergens

Common allergens include a wide variety of items that can be found indoors, outdoors, or are just part of our everyday lives.

  • Pollen produced by plants, grasses and trees
  • Cigarette smoke, industrial pollutants and particulates
  • Dust and dust mites, mildew and mold are found in even the cleanest of homes.
  • Household products containing common allergens such as kitchen cleaners and carpet cleaner spray
  • Artificial fragrances in laundry detergent and air fresheners
  • Flea collars contain powerful chemicals that may cause a contact allergy in your cat.
  • Lanolin is a potential allergen present in woolens. Wool can have a coating of natural lanolin. It’s a sort of grease derived from sheep which is the robust, natural “waterproofing” that shields the sheep in inclement weather.
  • Pesticides including commercial pesticides, herbicides and farm chemicals can be quite irritating to your cat’s skin. Your cat can be exposed directly to the chemical itself or indirectly by having contact with an item that has some of the chemical remaining on the item as a matter of production.

Signs and symptoms of allergies in cats

Your cat may have a variety of reactions to an allergen. Look for the following signs and symptoms of a potential allergy in your cat:

Skin reactions

“Miliary dermatitis,” may present as clusters of red, rash-like, raised lesions on your cat’s skin. It’s especially common along the back and neck, as well as the hind limbs and belly. This is a pretty extreme symptom that you can’t easily miss.

Inflamed ears and ear infections

The tender, delicate tissue of your cat’s ears may become inflamed as a primary response to an allergen, or the ears may become the site for a secondary bacterial infection, because your cat has been scratching wildly. You may also notice excessive build up of debris within the ear canals, ranging from a tan to dark brown/black debris or even yellow pus discharge. The ear may also be hot and tender. If you observe any of these signs, schedule a vet visit pronto.

Respiratory symptoms

Respiratory symptoms such as runny, itchy eyes, sneezing, wheezing, coughing, rapid breathing, and panting are often signs of airborne allergens. If your cat’s sneezing, wheezing and coughing is “unproductive” — meaning that your cat is not expelling any phlegm or other material from its mouth or nose — this signals an allergy versus a standard respiratory infection. Often, cats with allergic inflammation in their airways have fits of wheezing and/or coughing with a hunched, low-to-the-floor posture and full neck extension. This behavior is commonly confused with attempting to “cough up a hairball,” but actually may be signaling lower respiratory inflammation.

Eye inflammation

Inflammation of the conjunctiva can signal an allergy. The conjunctiva is the soft, wet scarf of protective tissue that surrounds the eye. When the eyes are itchy, burning, red, and producing discharge, it’s usually a condition called conjunctivitis. Secondary infection of the conjunctiva is common, and can endanger your cat’s vision if left untreated.

Digestive issues

Passing gas, vomiting, loose stools and diarrhea, all signal distress in the digestive tract. Cats, like ourselves, occasionally have imperfect digestion and elimination, but if these uncomfortable symptoms persist, you may be observing signs of an allergy-related issue.

Snoring and drooling

While some people think snoring and drooling in cats is cute, it can be a sign of allergies or another issue, including dental problems.

Bald patches

Your cat’s fur should ideally be soft, sleek and dense. Bare spots indicate hair loss or excessive scratching, both signals of possible allergic activity.

An occasional bout of indigestion or sneezing is probably nothing to worry about. However, if these symptoms begin to form a pattern, you are most likely looking at a condition which needs to be addressed. Skin issues like dermatitis can escalate quickly into infection, which usually requires antibiotics. Ear infections require prescription treatment and, if untreated, may impair your cat’s hearing.

Airvet app screenshots and invitation to download the free Airvet app

How are allergies in cats diagnosed?

The first step is to visit your vet in person with your cat. Your vet will help determine whether your cat is experiencing an unpleasant sensitivity or a true allergy. Many allergic conditions present multiple symptoms, involving both the skin and the digestive system, so a bit of detective work may be needed.

They might perform a skin scrape to look for mites, lice and bacterial infection. Since fleas don’t spend much time on the cat, they may use a flea comb to look for flea feces, which looks like black pepper. Since cats are such fantastic groomers, sometimes they lick away signs of fleas on their bodies.

Even if no evidence of fleas is found, your cat will likely be treated with a topical or oral flea killer and prevention for many months, but the effort against fleas doesn’t stop there. If you have other pets, they will need to be treated as well. Finally, your home environment will need to be thoroughly cleaned and vacuumed daily. In extreme cases, a professional exterminator may need to treat the inside of your home.

Allergy tests

In chronic allergy cases, your vet or a veterinary dermatologist may conduct allergy testing to identify the offending substance, by examining blood or skin samples. The purpose is to find out whether your cat is a candidate for desensitization. This is done by giving small doses of the allergen through injections or orally for months or years.

What are the treatments for allergies in cats?

The first line of defense against allergies will often aim to reduce inflammation.

  • Medicated shampoos and topical sprays can help alleviate itching.
  • An antihistamine may be recommended to suppress allergy symptoms. It is important to understand that your cat may need 7 – 10 days to respond to antihistamine treatment. Therefore, this medication may be ineffective for the occasional flare-up.
  • Fast-acting corticosteroids may be recommended for a brief duration. Steroids may be given to your cat orally or by injection. These powerful drugs have (somewhat) fallen out of favor due to many side effects. But, a short dosage can produce an immediate turnaround in your cat’s comfort.
  • Immunosuppressive drug therapy may be another option. Drugs like cyclosporine target the immune cells to reduce the hypersensitivity reaction. These drugs may take up to 30 days to show results.  Side-effects like nausea and lack of appetite are possible.
  • Antigen injections, or allergy shots, are another important consideration. Note that this is different from injected corticosteroids. Once a blood test or intradermal skin testing has identified the allergen, tiny amounts of the allergen are injected into your cat on a weekly basis. This process will desensitize (or reprogram) your cat’s immune response, making the immune system less reactive. In many cats, this will mean a significant reduction in severe skin itching, although some degree of itchiness may persist.
  • Antibiotics may be prescribed if your cat has developed a secondary skin infection as the result of an allergy.

Diet and allergies in cats

Your cat’s diet is an important place to explore when figuring out how to control allergies. Even though your cat may have enjoyed a certain food for years, they can still develop a food allergy or sensitivity.

Food allergy or food hypersensitivity can develop in response to almost any protein or carbohydrate. Your vet may suggest a hypoallergenic food trial with prescription hydrolyzed diet or a novel protein diet. Your kitty will need to stick to this menu exclusively for 12 weeks or more, to see if symptoms improve and/or clear.

The bottom line is that substances that were previously benign – from a once-favorite lambswool sweater to that turkey-licious cat treat that literally had your cat eating out of your hand – can suddenly turn from friend to foe. Some cats inherit a genetic predisposition to allergies. However, it’s virtually impossible for a cat parent to know this in advance of symptoms.

As always, observe your cat carefully. Early intervention is the key to recognizing a potential feline allergy and preventing any long-term negative effects to your cat’s health. The veterinarians at Airvet can assist you with any questions you may have about your cat’s allergies – and much more. Have you downloaded the FREE Airvet app yet? If not, what are you waiting for?

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