Food allergy in cats

isolated cat

Overview

Just like people, cats can develop allergies to certain ingredients in their food. This often causes skin and tummy problems.

Food allergies develop when the immune system mistakenly sees a food type as dangerous and overreacts to it. Food allergies usually develop by 4-5 years of age.

It’s not always easy finding out what your cat is allergic to but symptoms can be improved (and in some cases eliminated) if you feed your cat a diet that suits them.

What is a food allergy?

Some cats develop allergies to certain ingredients in their food. Food allergies develop when the immune system mistakenly sees a food type as dangerous and overreacts to it. Symptoms include skin and tummy problems, and will develop every time your cat eats something they are allergic to. Food allergies usually develop by 4-5 years of age.

Symptoms

The main symptoms of a food allergy in a cat include:

When to contact your vet

Contact your vet if your cat is showing any of the symptoms above especially if they are itchy all the time with no obvious explanation (such as fleas). Skin problems left without treatment often get worse quickly.

You know your cat best. If they don’t have the symptoms listed above but you are still concerned always contact your vet.

Diagnosis

Your vet will want to rule out other common causes of itchy skin before diagnosing a food allergy. Other common causes include: fleas, flea allergic dermatitis and atopy.

After ruling out other causes of itchy skin, your vet may want to conduct a food trial. This involves:

  • Stopping all usual foods and feeding an exclusion diet for at least 12 weeks (your vet will recommend which diet to feed).
  • If your cat’s symptoms get better during the trial, it confirms that they were reacting to something in their food.
  • If you allow your cat to eat anything else during the food trial, they might react to it and you won’t know whether the exclusion diet has been working or not. Your vet or vet nurse can give you some tips on how to make treats out of the special food so that you can still give your cat some variety.

Treatment

Feed a special diet for life

  • Feed your cat a diet that doesn’t trigger their allergy.
  • Don’t feed anything else (even human food or cat treats).

Find out what your cat is allergic to

  • Once your cat is settled on their special diet, your vet may recommend reintroducing food items one at a time, every 7-10 days.
  • If symptoms return, you’ll know that food item is a problem and that you need to avoid it.
  • By patiently repeating this process, you can gradually identify all your cat’s problem foods.

There are specially qualified skin vets who can help if you are struggling to control your cat’s food allergy.

Ongoing care

Be careful that your cat only eats food they aren’t allergic to.

  • Make sure they don’t help themselves to food in the house.
  • Provide anyone who feeds them (such as neighbours) with their special diet.
  • Be aware that most cat food and treats contain a mixture of ingredients that could trigger a reaction.
  • Treats need to be limited to foods that they don’t react to.

Outlook

Cats with food allergies can live a perfectly normal life without symptoms if they’re fed a diet that suits them. However, identifying problem foods and excluding them is often trickier than it sounds, especially because most cats roam the neighbourhood hunting and picking up scraps.

Speak to your vet for advice on how to manage food allergies. There are specially qualified skin vets who can help if you are struggling to control your cat’s food allergy.

Published: February 2019

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Written by vets and vet nurses

Illustrations by Samantha Elmhurst