Food Allergies in Cats: What to Look Out For

Posted in: Cat Health - Last Updated: September 1, 2023 - Author: Rebekah Carter
Posted in Cat Health 
Last Updated: August 31, 2023  
Author:  Rebekah Carter
tabby cat eating dry food from floor

Have you noticed your cat suddenly sneezing a lot lately, scratching at his fur, or chewing on his paws? Is your feline friend dealing with a terrible snore, after years of never making a peep while he was sleeping? Are these new food allergy symptoms appearing after you've made a change to your cat's diet?

Allergies are surprisingly common in cats, with most kitties developing issues somewhere between the ages of 2 and 6. Notably, your cat needs to be exposed repeatedly to the same product before they'll create an allergy or intolerance to it.

In cats, diagnosing food allergies can be a little tricky. Common symptoms like sneezing, scratching, and even gastrointestinal (tummy) troubles can also link back to a host of other ailments and conditions that have absolutely nothing to do with food. Additionally, while allergies are common in cats, they're often connected to things like certain materials, or cleaning agents. Only around 15% of all cat allergies come down to food.

Since your cat can't explain how he or she feels when eating a certain food, it's difficult to know exactly which ingredient might be causing the problem if your cat has issues. Much like dogs and humans, cats are susceptible to a range of allergies, and it's up to us as responsible pet owners to figure out what's going on.

Food Allergies in Cats vs Intolerances: What’s the Difference?

You may have noticed that we've mentioned food allergies in cats or intolerances when talking about dietary issues so far. That's because these are two very different things, though they both influence the response your cat has to certain foods and ingredients.

According to the Feline Nutrition Foundation, a food allergy in cats is a kind of reaction that the feline's body initiates when responding to a specific thing in the cat food.

Usually, cats develop food allergies because of certain proteins in meals, and in some cases, they can be very dangerous.

With allergies, the immune system in the cat identifies a potential protein or another product in the cat food as a dangerous invader, like bacteria or a germ. The body tries to fight this product off, which leads to reactions like sickness, rashes on your cat, and various other problems.

Food intolerances are a little different. Although intolerances cause various forms of discomfort for your cat, they're not usually as life-threatening as allergic reactions.

Usually, the symptoms of an intolerance center around the digestive system, causing issues like bloating, cramps, and diarrhea or smelly feces. A good way to determine whether your cat has an intolerance, or an allergy is to pay attention to its symptoms. You can also try switching their diet to a cat food for diarrhea or a cat food for smelly poop to see if this helps.

A kitty with an allergy might develop scabs on their skin from constant scratching or might start to lose their fur in patches due to regular licking. Alternatively, if your cat is vomiting a lot after a specific food, then it might have an intolerance. Experts generally agree that cats can have both allergies and intolerances at the same time.

ginger cat cleaning himself

Symptoms of Food Allergies in Cats

Intolerance to a particular food isn't a fun experience for your cat. If you notice your kitty having a lot of stomach issues, then you should definitely seek help from a vet and see what they suggest. You may need to switch your cat's food to something new.

However, for the purpose of this article, we're focusing a bit more heavily on cat food allergies. Notably, allergies for cats can potentially be life-threatening if they're allowed to continue without proper attention.

Your cat could experience a state of anaphylactic shock when exposed to something that he or she has a severe allergy to, which would mean that they stop being able to breathe. If you ever notice lethargy or trouble breathing in your cat, take them to an emergency vet immediately.

If your cat does have a cat food allergy, then this could last for a lifetime, meaning that you'll need to permanently ensure that the ingredient never appears in your cat's food. Unfortunately, these allergies can be difficult to diagnose, as it's tough for vets to create an allergen test that examines specific food issues. Some of the most common symptoms of your cat having an allergy might include:

  • Skin problems: Redness, itching, bald areas, abrasions, and scabs on the skin
  • Excessive scratching, or licking which may lead to bald spots
  • Fur ball problems caused by over-grooming and swallowing too much hair
  • Gastrointestinal problems caused by discomfort, such as vomiting and diarrhea
  • Wheezing or respiratory problems, including sudden snoring
  • Recurrent infections of the ears or eyes

As you may have noticed when sorting through the symptoms outlined above, one of the main reasons it's so difficult for vets to identify cat allergies, is that the symptoms can be the same as the signs for various other ailments.

For instance, your cat might scratch too often if they have an allergy, but this could also be a sign of something like flea dermatitis too. So a flea allergy must also be considered.

Taking your cat for a full examination by a vet is the only way to get a good insight into whether this is an allergen or not.

The Common Causes of Food Allergies in Cats

Just because your kitty doesn't seem to have any allergies or intolerance issues when they're young, doesn't mean that they won't develop a problem later.

It usually takes a few months or even years before your cat starts to develop an allergic response or intolerance to a certain food. However, once an allergy does develop, it's unlikely that it will just disappear.

Notably, while food allergies and intolerances can occur to any cat at any age, there are some breeds of cats at certain ages that are more likely to have issues. For instance, most cats develop allergies between the ages of 2 and 6. Additionally, some breeds seem to have more trouble with allergens than others. Siamese cats regularly suffer from allergies, for instance.

Get 30% off and FREE shipping on cat food!

U.S.A. only

To Find out why we recommend, click here

Though there's no guarantee that your cat will develop an allergy to any of the items below, these are some of the most common causes of allergies and intolerances:

  • Artificial colors and preservatives: There’s a reason why doctors and vets always recommend staying away from artificial colors if you can. Some of the cheaper cat food brands use artificial colors to make items seem more appealing. There’s also a chance that there will be preservatives in your cat’s food to make sure that it can last for as long as possible. Unfortunately, these artificial ingredients often cause allergy issues.
  • Corn and grain products: In most cases, corn and grains in cat foods are a form of filler. They don’t do much for your cat nutrition-wise, but they’re there to help the cat feel full, and make it seem like you’re getting more value for your money. Cornmeal products can often lead to significant problems with cat food intolerances and allergies. The reaction to corn is usually very easy to see as it appears in the form of itchy and flaking skin. Try switching to a grain free cat food.
  • Dairy products: Despite What popular culture might have you believe; cats and milk don’t actually go together as well as it might seem. Most cats just don’t have the right amount of lactase enzymes, which means they can’t digest dairy in significant quantities. Your cat is probably lactose intolerant, so feeding it bowls of cow milk (not kitten or cat milk), could lead to vomiting and other gastrointestinal issues.
  • Meat byproducts: Meat is one of the ingredients that you should have plenty of in your cat foods and dry cat biscuits. However, meat byproducts aren’t as good for your cat as they sound. Usually, these “byproducts” are inexpensive ways to fill the food with extra bulk, so it seems like you’re getting more value for your money. Byproducts include things like fats, tissues, and organs that us humans definitely wouldn’t eat. These byproducts don’t have the best quality control, and they may contain ingredients that aren’t great for your cat.
  • Seafood: Just like milk, your furry friend might seem like she loves tuna, but the truth is that seafood isn’t the best product for your cat. Seafood is becoming increasingly common as a cat allergy, particularly when you’re feeding your cat fish and tuna that has ingredients like preservatives you may not be aware of.
ginger cat with white feet eating from white bowl

How Do Vets Test for Cat Food Allergies?

To determine whether your cat has a food allergy, your vet will usually try a few different tests. The most common way to find out what's causing the problem for your cat is to start with an exclusion dietary trial (elimination diet trial).

This is where you start feeding your kitty a pretty bland hypoallergenic diet. These foods are specially made with proteins so small that they very rarely cause any kind of cat's symptoms or reaction.

Gradually, you can begin to introduce new bits of food and ingredients into the diet and keep an eye on how your kitty responds.

Usually, the exclusion diet will last for a fixed period of time, which your vet will suggest based on any allergic reaction symptoms your cat is displaying. If your cat has skin issues, for instance, it might continue using the restricted diet for about 12 weeks. Gastro problems (stomach issues and vomiting) usually clear up a bit faster.

The key to success with elimination diet trials is making sure that your kitty doesn't eat anything other than the food suggested by the vet. This includes treats and tidbits from your table – no matter how much you want to keep your cat happy. Respond to your vet with insights into how your kitty has been while eating the newly recommended food.

Remember, like with most health-related tests for your kitty, it's important to be as honest as possible about the results with your vet. This includes letting your vet know if your cat refuses to eat the food you give them or tries to pull other food out of the trash.

After the trial period with the anti-allergenic food comes to an end, your vet will give your cat a full examination to see how symptoms have changed or improved before you start adding other ingredients back into the kitty's food bowl.

If the symptoms have stayed the same, there's a chance that your cat's ailments have nothing to do with food, which means that you might need to look into the chances of other problems.

Introducing One Ingredient at a Time

It's unlikely that your vet will ask you to keep your kitty on their new exclusion diet forever. However, there's a chance that it will take several months before you can fully move your cat onto a different kind of food. That's because you have to introduce each new ingredient to your cat's diet one by one carefully and give it time to see if the symptoms flare up again.

In some situations, you may think that you've discovered the source of your cat's food allergy problems, and then realize that your kitty is actually intolerant to various ingredients, and allergic to a couple more.

If this is the case, then you might have a hard time finding pre-made cat food that's suitable for your feline friend. You might have to consider making the food that your cat eats from scratch and storing it in a freezer.

Testing various foods and ingredients with your cat one by one can be a lot tougher than it seems. If you've got more than one cat in the household, you may need to give both of them allergenic food to ensure that they're eating the same meals.

That stops the risk of your cat simply eating the other feline's food when they don't like their own.

If there are other pets in your house (like dogs) which could give your cat access to additional meals, you'll need to be extra careful with those too. It's often surprisingly easy for cats to find other sources of food if they're not happy with what's in their bowl.

The good news? The extra work will be worth it when you know your cat can enjoy their meals without worrying about any allergic or intolerant responses.

tabby cat eating from orange food bowl

Handling a Cat Food Allergy

Allergies and intolerances aren't just problematic for your cat, they're a huge pain for you too. You'll need to be extra cautious about how you dispose of uneaten food so your cat can't gain access to it. Plus, you'll have to set rules for everyone who comes into your house, so they don't accidentally give your feline friend any treats or food from their plate.

However, no matter how complicated cat food intolerances and allergies can be, you can't afford to simply ignore the issue.

Food intolerances and allergies can last a lifetime and make it almost impossible for your cat to enjoy a happy and healthy life. Learning how to cut dangerous foods out of your kitty's diet is crucial to ensuring that they get the nutrition they need, without the dangerous side effects.

Remember, it's not just the wet cat food that your kitty eats that might be causing its allergy. Your cat can also have allergic responses to treats and irregular foods too. Make sure that you keep those in mind when you're exploring your options with dietary elimination trials.

If you notice that your cat does have one or two allergies that are easy to eliminate from their food, then your vet might recommend some options for food options that are less likely to cause allergic responses. There are a lot of specialist anti-allergenic meal options out there for kitties these days.

Don't just choose a new food or a novel protein diet for your cat at random without speaking to your vet first, however, as they may need to give you special advice on how to replace proteins that your cat can no longer get from their new foods.

Additionally, remember that introducing your cat to any new food needs to be a slow process. Introducing new ingredients and dietary choices to your cat can sometimes lead to sickness and diarrhea.


What is the most common food allergy in cats?

The most frequent food allergy in cats typically involves proteins present in their meals. In particular, ingredients like beef, dairy, chicken, and fish are common culprits for allergic reactions in cats. Nonetheless, it's crucial to remember that each cat may have unique sensitivities, and the prevalence of specific food allergies may differ.

What food is best for cats with allergies?

For cats dealing with allergies, the most suitable food options tend to be hypoallergenic or limited-ingredient diets, which help reduce the likelihood of provoking an allergic response. These diets often feature unique protein (like venison, rabbit, or duck) and carbohydrate sources (such as green peas or sweet potatoes) that the cat hasn't encountered before. It's vital to speak with a veterinarian before altering your cat's diet, as they can suggest specific products or recipes tailored to your cat's individual requirements and guide you through a smooth transition to the new food.

What does a food allergy look like in cats?

In cats, a food allergy can manifest in several ways, impacting the skin, digestive system, or both. Typical indications of a food allergy in cats involve itching, red or inflamed skin, increased grooming or scratching, hair loss, skin sores, ear infections, vomiting, and diarrhea. The intensity and occurrence of these symptoms can vary from one cat to another, making it essential to seek advice from a veterinarian for accurate diagnosis and management if a food allergy is suspected.

Can cat allergies be cured?

While cat allergies, especially food allergies, cannot be entirely cured, they can be effectively controlled by pinpointing the specific allergen and removing it from the cat's diet. Collaboration with a veterinarian is crucial for accurate diagnosis and treatment. They might suggest a hypoallergenic or limited-ingredient diet to lessen the chances of provoking an allergic response. By attentively managing their cat's diet and surroundings, owners can substantially enhance their pet's well-being and alleviate or eliminate allergy-related symptoms.

Food Allergies in Cats: Summary

Food allergies in cats are a common headache for a pet owner with feline friends. Lots of creatures, just like us, suffer from allergies when they're exposed to a specific ingredient or stimulant for long periods of time. Your cat could even suddenly become allergic to the food he's eaten all of his life, or the treats that he enjoys the most.

As difficult as it can be to determine which foods your cat is allergic or intolerant to, and find an alternative food for them to eat, it's important to ensure that you put the work into giving your cat the right nutrition.

Exposing your feline to foods that interact negatively with a cat's immune system could lead to some very serious side effects. You don't want to put your furry pal at risk.

As pet parents, if you're concerned that your cat might have an intolerance or an allergy, seek assistance from your vet as soon as possible. They will be able to professionally advise on prescription diets or a hypoallergenic diet.

Get 30% off and FREE shipping on cat supplies!

U.S.A only

To Find out why we recommend, click here

Affiliate disclosure : We Love Cats and Kittens is a participant in several affiliate programs including the Amazon Services LLC Associates Program, and the Chewy affiliate program. These are affiliate advertising programs designed to provide a means for sites to earn advertising fees by advertising and linking to products on their sites. If you click on links in our blog posts and articles we may be paid a commission.

About the author

Rebekah Carter is a dedicated animal lover. Her Savannah cat, Roscoe, has a lot of attitude, while her Maine Coon, Dukino, is full of love. When not writing, she’s looking after her cats and researching ways to help them live their best possible life. Her passion for animals and natural skill for writing led her to pursue pet blogging.