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Home > Cats > 11 Common Cat Allergies: Their Symptoms & Causes

11 Common Cat Allergies: Their Symptoms & Causes

cat scratching

Cat allergies are similar to human allergies. They are caused when your cat comes into contact with an allergen and the immune system reacts, thinking it is a harmful toxin. The immune system produces antibodies and causes signs such as sneezing, a runny nose, headache, dehydration, and other possible reactions.

Allergies can form at any time in a cat’s life, and nobody is sure exactly why or how they develop. Treatments include homeopathic, over-the-counter, or prescription-based medicines, along with the avoidance of any known allergens.

Below are some of the most common cat allergies, as well as allergy signs and possible treatments.


The 6 Environmental Cat Allergies

kitten playing with flowers
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Environmental allergies are those that are caused by allergens within a cat’s surrounding environment. This can include both their indoor and outdoor environment, and they make up the most common group of allergens for cats. They can also be among the most difficult to identify, which makes their treatment very difficult. Some common examples to look out for include:

1. Pollen

Pollen, or seasonal allergies, are similar to hay fever in humans because they are caused by pollen from plants and grass.

However, where pollen allergies in cats differ is in the signs. While humans develop a runny nose and watery eyes and may start sneezing and coughing, cats will usually develop something called atopic dermatitis, which means that their skin will become itchy, flaky, and red where it comes into contact with the pollen.

Treatment requires keeping your cat indoors to prevent them from coming into contact with pollen and/or taking antihistamines, including over-the-counter and prescription medications.

2. Grass

Grass allergies are a type of pollen allergy. Cats can be allergic to pollen from any grass, although the most common is that of Bermuda grass.

Like other pollen allergies, a grass allergy will usually lead to dermatitis-like signs such as itching and irritation of the skin. While this can occur around the feet and legs where your cat walked through the grass and disturbed the pollen, it is important to remember that pollen is airborne and, as such, can affect any area of your cat’s body.

Topical creams can prove very effective against this type of allergy because they relieve the signs and prevent your cat from continuing to scratch and bite at the reaction site.

3. Mold

Mold gives off spores, and your cat’s immune system could view these spores as being a dangerous invader. This can lead to respiratory problems if inhaled, digestive problems if ingested, and dermatitis if touched.

Mold can form on almost any surface and is sometimes found on pet food, especially dry food that is kept in sheds and damp pantries.

Because cats groom themselves by licking their fur, this increases the likelihood of mold spores being transferred from the body into the stomach, via the throat and digestive system.

Look for the source of the mold. Check their food source because even if it isn’t kept in the shed, it can still become moldy. Look in areas where your cat enjoys relaxing, and don’t forget to include outdoor areas in your search.

Image By: danbar44, Pixabay

4. Dust

Dust allergies are common in people and can also be found in cats and dogs. Specifically, this is an allergy to the protein Der p1, which is found in dust mite feces. Consumption or inhalation of this protein can lead to respiratory problems including coughing and wheezing. It can also include skin and dermatitis complaints, such as skin lesions.

Cats that enjoy sleeping in basements and attics are most prone to coming into contact with dust mites and it will require that you carefully clean your home more often. You may even need a special vacuum or cleaner that specifically targets this type of allergen.

5. Chemicals

Chemicals are found in cleaning products as well as our own perfumes and other products, and cats can be as allergic to these as people are. If it is your perfume, this means that your cat rubbing themselves against you and being affectionate could be making them ill. An allergy to clothes detergent means sleeping on the bed or in piles of washing can cause skin rashes.

You should try to identify the cause of the allergy and then look for alternative products. For example, try a different washing powder or wear a different perfume to stop your cat’s allergic reaction.

6. Flea Allergies

Flea allergies are unfortunately common in cats and are specifically caused when a flea bites your cat to suck its blood. Some of the flea’s saliva is injected into the skin and the protein that it contains causes an allergic reaction. A single flea can be enough to cause a severe reaction in some cats.

You may have to give your cat steroids or strong antihistamines, probably after having the problem diagnosed by a vet to ensure that you get the right treatment. Flea allergies can be a real blight for your cat, and you should take action quickly to prevent challenging skin complaints.

cat flea treatment
Image Credit: AlexDonin, Shutterstock


The 2 Main Food Cat Allergies

Like people, cats can be allergic to certain foods, although food allergies are less common than flea and environmental allergies in felines. If your cat suffers from a food allergy, you will likely have to introduce an elimination diet to specifically identify the food or foods that your cat is allergic to.

7. Dairy

Many cats are lactose intolerant, while some suffer a full allergic reaction to dairy foods including milk and cheese. Owners are advised not to give dairy products to cats, but some may steal milk. Avoidance is the best cure for this particular allergy, as there is no reason to feed cats dairy products.

kitten drinking milk
Image By: ChristopherPluta, Pixabay

8. Grain

Grain is not considered a species-appropriate ingredient, and your cat may suffer from a grain allergy or sensitivity. While some commercial foods do use grains as fillers and binders, there are a lot of grain-free alternatives now on the market that make this an easy fix.


The 3 Less Common Food Cat Allergies

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Cats can also be allergic to meat proteins and other food ingredients. Signs are typical and can include respiratory and dermatological signs. If you believe your cat is allergic to a common meat protein like chicken, you can try feeding a food that utilizes a novel protein, such as buffalo, or you can change to a different common protein. If the allergy signs stop, your cat was allergic to something in the original food. It is worth noting that if signs persist, it is possible that your cat is allergic to something else that is common in both foods, or may even be allergic to more than one common ingredient.

Common feline food allergies include:

9. Beef

10. Fish

11. Chicken



Although food allergies do occur in cats, the most common forms of allergy are environmental and flea allergies.

Regardless of the allergen, cats tend to show respiratory signs as well as dermatological signs like itchy and irritated skin.

Try to identify and remove allergens and consider antihistamines and even topical steroids, with a veterinary recommendation, to help combat and stay on top of allergic reactions.

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