Cat Food Allergies: Symptoms & Diagnosis

If you suffer from food allergies, you know just how annoying they can get. Not only do they prohibit you from eating certain delicious dishes and cuisines, but they can also cause itchy red rashes to appear all over your body and even send you into anaphylactic shock. 

Unfortunately, while uncommon, cats can also suffer from food allergies. With many of the same signs and symptoms, food allergies can be quite distressing for your feline friend. If you suspect your cat to have a food allergy, it is crucial to get an accurate diagnosis from your veterinarian and rule out any other possible illnesses. 

Other than the signs and symptoms of cat food allergies, we will also discuss common cat food allergies and how they are diagnosed and treated. If there is a topic you are especially interested in, please feel free to jump directly to it using the links below.

• What Is A Food Allergy?
• Signs Your Cat Is Suffering From A Food Allergy
• Common Cat Food Allergies
• When Should I Take My Cat To The Vet?
• How Are Cat Food Allergies Diagnosed?
• How Are Cat Food Allergies Treated?
• Cat Food Allergies: Frequently Asked Questions
• Final Notes

What Is A Food Allergy?

Your immune system protects your body by fighting off germs and other harmful substances, keeping you healthy. However, sometimes it mistakes a regular, harmless substance as an invader and attacks that instead. With food allergies, your immune system deems a certain food or a substance in a food, such as a protein, to be dangerous and triggers its protective response.¹ 

Out of all the allergies cats can have, food allergies are the third most common type, just after flea allergies and inhaled environmental allergies.² Responsible for a variety of aggravating symptoms, ranging from skin rashes and hives to gastrointestinal issues such as diarrhea, food allergies can turn deadly if they impact your cat’s ability to breathe. 

Food allergies are also often confused with food intolerances, which are much less severe and usually non-life-threatening. While food allergies revolve around the immune system, food intolerances only impact the digestive system.³ Cats, for example, are often lactose intolerant. Losing the ability to properly digest the sugar present in milk as they reach adulthood, cats can drink a little milk but it may result in an upset stomach. 

Signs Your Cat Is Suffering From A Food Allergy

Food allergies can often affect a cat’s body the same way as other allergies, so it is important to monitor and document when exactly your cat is exhibiting these symptoms. Being able to identify the signs and symptoms of cat food allergies is also the first step to getting your kitty the help they need. The sooner they are diagnosed, the sooner you will be able to alleviate their discomfort. 

If your cat is suffering from food allergies, they may have:

• Itchy, irritated skin
• Fluid-filled lumps on the skin
• Diarrhea
• Flatulence
• Vomiting
• Discharge from the eyes and nose
• A swollen face
• Ear or paw infections

Common Cat Food Allergies

Only a small number of cats have food allergies, but there are certain foods that cats are more likely to be allergic to. It may surprise you that rather than grains like corn and oats, cats are more prone to be allergic to animal proteins.⁴ In fact, the most common cat food allergies are all animal proteins easily found in manufactured cat food. 

The most common cat food allergies include:

• Chicken
• Egg 
• Beef
• Fish

When Should I Take My Cat To The Vet?

If your cat is exhibiting food allergy symptoms, set up an appointment with a vet to determine what exactly your cat is allergic to, whether it ends up being food or another allergen. 

However, if your cat seems to have difficulty breathing or is suddenly vomiting, drooling, or appearing uncoordinated after eating, seek veterinary help immediately as they could be experiencing anaphylactic shock. While rare, anaphylactic shock is a life-threatening emergency. With quick action, your vet will be able to administer adrenaline injections, antihistamines, anti-inflammatory drugs, and fluids to save your kitty’s life.⁵ 

How Are Cat Food Allergies Diagnosed?

Sadly, diagnosing food allergies in cats can be a long, frustrating process that requires a lot of patience and tough love. Unlike diagnosing human allergies, despite their availability to be purchased online, there are no accurate blood, skin, or saliva tests that can pinpoint the exact allergen affecting your cat.⁶ For now, the most reliable way to determine whether a cat is allergic to a certain food is to remove all currently fed foods from their diet and begin a hypoallergenic diet trial, also known as an elimination diet trial. 

The hypoallergenic diet trial should last around eight to 12 weeks, and there are two most common types:

The novel ingredient diet: This diet requires feeding your cat food made with proteins and carbohydrates they have never eaten before. Because these ingredients are completely new or “novel” to your cat’s immune system, they will be tolerated since an allergy would not have had enough time to develop. Some novel proteins typically featured in this diet include rabbit, venison, and kangaroo. 

The hydrolyzed diet: Also known as the low-molecular-weight diet, this diet is usually composed of common cat food ingredients, such as chicken, that are broken down to be very small and below the allergenic threshold. Molecularly altered into tiny fragments, your cat’s immune system will have trouble registering these ingredients as allergens even if your cat is allergic to them. This diet tends to be suggested for cats that have already tried a wide range of proteins and carbohydrates. 

Keep in mind that for the hypoallergenic diet trial to work, you must strictly follow your veterinarian's directions and ensure that the only food your cat eats is what is prescribed to them. Anything from a small piece of food accidentally dropped on the ground to flavored cat toothpaste could alter the results of the trial, so it is crucial to keep a close eye on your kitty and watch what you allow them to ingest. Unless it is also hypoallergenic and made as a supplement to your cat’s veterinary prescribed food, you should steer clear of giving them any treats as well. 

Taking part in such a long diet trial can be very difficult for your cat. They may even refuse to eat their new food. Contact your veterinarian immediately if this is the case. It might take trying a few different foods to find one your cat can accept. 

After the hypoallergenic diet trial, if your cat’s allergy symptoms cease, they must continue on with a diet challenge to confirm that a food allergy is what’s causing their condition. Your cat will be put on their original diet. If their resolved symptoms arise again or even worsen, they are diagnosed with a food allergy. Further, to conclude what exactly your cat is allergic to, they will resume eating the hypoallergenic diet until symptoms stop once again and then be individually introduced to ingredients in their original diet. The ingredient that causes their symptoms to flare up is what they are allergic to. 

How Are Cat Food Allergies Treated?

There is no cure for cat food allergies. The only way to alleviate your cat’s symptoms and improve their condition is to totally eliminate the ingredients they are allergic to from their diet. This requires you to closely examine the ingredient and nutrition labels of any food, treats, and supplements you give to your cat. 

Vet-recommended food or prescription food, similar to what your cat had during their hypoallergenic diet trial, can be a good choice. It can also be hard to avoid cross-contamination in manufactured cat food, so sometimes homemade cat food can also be a solution, as long as your cat is getting the essential nutrients they need. With the help of a veterinary nutritionist and balancing supplements, it is possible to prepare your cat’s food yourself if desired. 

Cat Food Allergies: Frequently Asked Questions

How long does it take for a cat food allergy to go away?

For cat food allergies, any gastrointestinal issues should resolve in around 2 weeks. Any skin problems, such as itchy skin or skin rashes, however, may take longer to heal. If you notice your cat experiencing prolonged effects caused by food allergies, consult your veterinarian to see if there are any other underlying causes. Cat food allergies cannot be cured, so it is important to keep the ingredients your cat is allergic to out of their diets. 

How do you prevent food allergies in cats?

While there is no true way to prevent food allergies in cats, you should always feed your cat a high-quality diet, avoiding low-quality food such as food with too many grain fillers. From a young age, it is also a good idea to feed your cat a variety of proteins. Remember to always feed your cat a species-appropriate diet as well. 

What helps cat allergies fast?

Antibiotics can treat any skin infections your cat may have developed due to aggressive grooming caused by allergies. Antihistamines can help your cat with itching. Always discuss with your vet before giving your cat any over-the-counter medications. Your vet will help you determine the safety of these medications and what dose to give your cat if approved.

Final Notes

While it is impossible to cure food allergies in cats, by keeping a watchful eye on the ingredients present in their food, snacks, and supplements, you can avoid allergens and still ensure the health of your feline friend. If your cat has an immediate severe allergic reaction, seek veterinary care as soon as possible.