Food allergies and food intolerance in cats

Are you worried because your cat is showing symptoms such as diarrhoea or vomiting and seems to be itching? The cause could be a food allergy in your cat. An allergy of this sort does not necessarily occur with a change of food, as many cat owners assume, but can also happen spontaneously with cat food that the cat has been used to for many years. We explain what the cause may be and how you can help your cat.

What is the difference between a food allergy and food intolerance?

The terms “allergy” and “incompatibility” or “intolerance” are usually lumped together when complaints occur in our animals that seem to be due to what they are eating. Basically, both disease patterns are triggered by an ingredient that impairs functions such as digestion or causes physical symptoms of illness and can lead to severe discomfort in the cat. The symptoms of food allergy and food intolerance are therefore similar and do not indicate which of the two conditions is present. 

The difference lies in the body’s reaction to the problem ingredient. With a food allergy, the cat’s immune system reacts to certain ingredients in the cat food. The ingredient in question is perceived as a pathogen and fought as an invader. An overreaction occurs, which manifests itself in typical allergic reactions. 

With food intolerance, on the other hand, it is not the immune system that reacts, but the gastrointestinal tract. In this case, there is a metabolic disorder. This means that certain ingredients cannot be processed properly and the digestive process is disrupted. In both cases, the food must be changed for the benefit of the cat. 

Recognise whether it is an allergy or an intolerance Food allergies and food intolerance in cats

Symptoms of food allergies and food intolerance in cats

The symptoms of food allergies and food intolerance can be quite different. The following complaints can give a first indication: 

  • Diarrhoea
  • Vomiting 
  • Flatulence 
  • Allergic reaction of the skin such as redness, skin inflammation, ulcers
  • associated with itching
  • Ear infections 
  • Respiratory problems 
  • Weight loss 
  • Water retention
  • Growth disorders in young cats 
If these symptoms occur, it is advisable to consult your regular vet, as he or she can determine by means of a blood test whether an allergic reaction is present in the body. However, the blood test does not give any information about which ingredient in the food is causing the allergic reaction. 

What helps to deal with food allergies in cats? Exclusion diet!

Some cats develop an allergy to an animal protein source and thus can no longer tolerate a certain type of meat. Other animals react to artificial additives in cat food that are added by the manufacturer – such as preservatives, colourings, aromatics or flavourings. These additives are often found in low quality cat food, where cheap ingredients are used to make the food tastier or more attractive. It is therefore always advisable to choose a high-quality cat food that does not contain any artificial additives.

To find out which ingredient in the cat food triggers the allergic reaction, your only option is to put your cat on an exclusion diet. Cats are creatures of habit, especially when it comes to their food. However, it is important to find out what is causing the health problems in order to avoid them in future. The exclusion diet may last a few weeks until it is clear which ingredient in the food is causing the problem for your cat. 

It is important to avoid any snacks in between and to stick to the diet plan. This is particularly difficult with outdoor cats. To prevent the cat from eating other foods during an exclusion diet, it should not be allowed to leave the home while it is on the diet. 
In the case of a food allergy or intolerance, only an exclusion diet will help. Cats must not eat any other food or treats during the exclusion diet
If there are other animals in the household – such as dogs – make sure your cat does not eat their food. Also make sure that your cat does not have access to any other food in the house.

Overview of food ingredients that can trigger allergies in cats:

  • Meat or fish protein 
  • Soya
  • Milk or milk products 
  • Eggs 
  • Sources of carbohydrate such as wheat
  • Artificial additives 
For a successful exclusion diet, treats must not be given Cats must not eat any other food or treats during the exclusion diet

How do I go about introducing an exclusion diet?

The easiest way to start is to change your protein source. Give the cat a different type of meat for a short period. Since the carbohydrate source – wheat or potato, for example – could also be the cause, do not change that for now but deal with it later in the exclusion diet if necessary.

If the symptoms disappear, you can conclude that it was the type of meat or protein source that triggered the allergy. It also tells you which types of meat your cat tolerates well. When the symptoms have subsided completely, start the provocation test. This means reintroducing the previous meat component, which your cat has eaten before and its body already knows. If the old symptoms reappear within two weeks, this confirms the food allergy. Over the next few weeks, provide other protein sources carefully. If the symptoms recur, the suspicion of an allergy to certain types of meat increases. 

It is advisable to switch to monoprotein food in the diet. This means food with only one type of meat, which allows you to draw conclusions more easily about each protein source. Vets advise giving unusual meats to a cat that it has not eaten before if it is prone to allergies. This is because the risk of allergies is lower here. When your cat eats varieties such as duck, horse or lamb meat for the first time, its body is not yet familiar with the protein sources. No antibodies are therefore present in the immune system and symptoms are less likely to occur.

Why is the provocation test so important?

Many cat owners wonder why a provocation test is necessary if the cat stops showing symptoms after the change. If your cat has an allergy, it is important to avoid the ingredients that trigger it permanently. Only with the help of the provocation test is it possible to identify what is actually the cause. Was it the type of meat or an additive? Or maybe the cause was not the food at all, but something the cat ate on the side. If you do not know the cause, you cannot solve the problem, and this can cause long-term problems for your cat, such as being overweight or underweight and kidney disease.

Determine food allergy and food intolerance in the cat by means of a provocation test. Carrying out the provocation test with an exclusion diet in cats

What is the best way to help my cat?

Before or during the exclusion diet, when the cause is not yet clear, the most important thing is to relieve the symptoms of the food allergy. Please talk to your vet, they can prescribe the right medication and ointments to alleviate discomfort such as itching or inflammation during the transition period, to prevent cats from scratching or licking. Otherwise, skin inflammations can worsen.

A food allergy is not curable, but only treatable by removing the cause in the food that leads to the overreaction. This is why it is so important to stick to the exclusion diet – even if the cat is not keen – in order to help it in the long term.

And the last step is to eliminate the trigger ingredient. Vets refer to this as an elimination diet. The allergens that cause the symptoms are strictly avoided.  

You can also make the cat food yourself on an exclusion diet. However, it is important to ensure that our four-legged friends continue to get all the important nutrients they need. If you decide to go down this route, we recommend setting up a feeding plan with your vet or a cat nutritionist. In this way, you can create an individual diet plan to identify the causative allergens and cover all the vital nutrients for cats. 

How can I help the cat with a food allergy? What is the best way to help my cat if it has a food allergy?

Does my cat need diet food for a food allergy?

An expensive diet food is not always necessary for cats suffering from allergies. Once the culprit has been found, it is usually enough simply to avoid the ingredient. A diet food usually only means that there is a single protein source (a so-called monoprotein food) and it contains ingredients with “low allergy risk”. In such a case, it is enough to change from a cheap industrial food to high-quality cat food. Like the diet food, these high-quality foods do not contain gluten, soya or artificial additives such as aromatics, colourings or flavourings. Try comparing the manufacturer’s ingredients. This is because ingredients such as a high water content or wheat are cheaper than high-quality meat. The artificial additives are supposed to make the food more attractive, but unfortunately it comes at the expense of your cat’s health and vitality. We therefore recommend choosing a high-quality cat food. Your cat will thank you. 

Diet food is not always the right solution for allergies Does my cat need a diet if it has food allergies?