Food Allergy in Cats – Symptoms, Causes, and How to Choose the Right Cat Food

Constant scratching, digestive problems, recurring ear infections – have you noticed these symptoms in your feline friend and suspect that your cat may have a food allergy? A food allergy in cats is an immune system reaction to a specific ingredient in their diet (most commonly a protein source, grains, or artificial additives). It manifests as skin problems (itching, skin inflammation, redness, scabs, etc.) and digestive issues (vomiting, loose stools, gas, and diarrhoea).Confirming a food allergy requires an elimination diet based on a new protein source that your cat has never eaten before. Switching to hypoallergenic cat food may also be a good option.Table of Contents

1. Food allergy in cats – symptoms to watch out for

2. Food allergy in cats – the most common causes

3. Allergies in cats – scratching, vomiting, redness. What should you do?

4. How to choose the right food for a cat with food allergies?

5. Food allergy in cats – summary

Food allergy in cats – symptoms to watch out for

Food allergy symptoms in cats can be divided into two categories: skin-related and digestive. The most common skin symptoms include:

• intense itching, particularly around the head, neck, ears, and base of the tail (scratching around the ears can lead to recurring ear infections),

• redness and skin irritation, sometimes accompanied by visible bumps or small spots,

• hair loss and thinning fur in areas affected by excessive scratching or licking,

• scabs and oozing sores caused by scratching the skin,

• dull, poor-quality fur resulting from chronic irritation.

The most common digestive symptoms include:

• recurring vomiting,

• loose stools or chronic diarrhoea,

• excessive gas and bloating,

• more frequent bowel movements than usual.

Importantly, similar symptoms may occur in cats with food intolerance. Unlike a food allergy, food intolerance does not involve an immune response but usually results from difficulty digesting a particular dietary ingredient (e.g., due to a lack of certain enzymes).

Food allergy in cats – the most common causes

A food allergy in cats occurs when the immune system reacts to a particular ingredient in food, mistakenly identifying it as a threat. The most common allergens include:

• Animal proteins – protein sources commonly found in cat food formulas (chicken, beef, and certain fish) can trigger allergic reactions.

• Grains – particularly wheat, corn, and soy (found in many pet foods as fillers or carbohydrate sources).

• Artificial additives – colourings, preservatives, and flavourings used in cheaper pet foods may worsen existing allergy symptoms.

Importantly, an allergy to a particular ingredient can develop even after years of eating it – it does not necessarily appear after the first exposure.

Allergies in cats – scratching, vomiting, redness. What should you do?

If you suspect your cat has a food allergy, the best approach is to introduce an elimination diet. An elimination diet involves temporarily switching to food containing a new protein source that your cat has never eaten before (e.g., duck, wild boar, or rabbit). Another good option is hydrolysed cat food, in which proteins are broken down into very small particles that the cat's immune system does not recognise as allergens. Below, we explain how to carry out an elimination diet correctly.1. Start by consulting your veterinarianA visit to the veterinarian will help rule out other causes of skin or digestive problems and allow you to choose an appropriate elimination diet for your cat.2. Follow the elimination diet for 8–12 weeksFor 2–3 months, feed your feline friend only the selected food. Treats, table scraps, vitamin supplements? Eliminate all these extras from your cat's diet, as even a small amount of another protein source can undermine the entire process.3. Carry out a food challengeReintroduce the previous ingredient into your cat's diet. If symptoms return within 3–14 days, this will help confirm which ingredient is causing the allergic reaction.

How to choose the right food for a cat with food allergies?

A cat with a suspected food allergy should be fed a formula containing a protein source it has never encountered before, free from grains and artificial additives, and with a limited number of additional ingredients. The best food for cats with allergies contains just one protein source (monoprotein cat food) or hydrolysed protein (hydrolysed cat food, in which proteins are broken down into particles so small that the immune system cannot recognise them as allergens).Brit offers a range of complete grain-free cat foods suitable for cats with allergies. Some options include:

• Brit Veterinary Diets Cat Gluten & Grain Free Ultra-Hypoallergenic – a formula containing insect protein, omega-3 and omega-6 fatty acids to support healthy skin and fur, and probiotics to help maintain a balanced gut microbiome.

• Brit Grain Free Veterinary Diet Cat Hypoallergenic – a complete dry food based on hypoallergenic salmon (a source of omega-3 fatty acids).

• Brit Care Cat Grain-Free Sensitive – a recipe containing hypoallergenic insect protein and herring as a source of omega-3 and omega-6 fatty acids.

Food allergy in cats – summary

A properly selected diet can bring noticeable improvements in cats suffering from food allergies. Here are the key points to remember.

• Food allergies in cats primarily manifest as skin problems (itching, redness, hair loss) and digestive issues (vomiting, diarrhoea, bloating), sometimes accompanied by recurring ear infections.

• The most common food allergens in cats include animal proteins, grains, and artificial additives.

• To confirm a food allergy in your cat, introduce an elimination diet based on a new protein source for 8–12 weeks, excluding all other foods during this period.

• When choosing food for a cat with allergies, opt for monoprotein or hydrolysed protein formulas, free from grains and artificial additives, and enriched with omega-3 and omega-6 fatty acids.

Read also: Can Cats Drink Milk?