Elimination diets for dogs: what, when and how

Updated January 2021

Not all dogs are created equal. While in a lot of ways this is obvious – dogs come in all different shapes, colour and height – there are less obvious ways in which dogs differ, including their ability to digest and process certain foods.

Put another way, not all dogs can eat the same types of food – some dogs have an allergy or an intolerance to specific foods. Knowing the difference between the two, and if your dog has either, is important to keeping them happy and healthy.

So, what is the difference?

A food allergy causes your dog to mount an immune response to an ingredient found in food (usually a protein), even a tiny amount may trigger an allergic reaction and it can be severe and even life-threatening. These reactions can occur within minutes to hours of ingesting of a food that the body has declared harmful.

In contrast, a food intolerance is a physiological response to a food that does not affect the immune system and it is never life-threatening. Symptoms of food intolerance generally take longer to appear than symptoms of allergies. Depending on the type of food intolerance your dog has, he may be able to eat small amounts of a problem food without a reaction.

Both a food intolerance and allergy can be caused by any specific type of ingredient with dairy, chicken, egg and beef being some of the more common culprits. A food intolerance can also be caused by too much fat, too much or too little fibre or a diet that has other properties that don’t agree with your dog

Identifying the culprits

If you’re concerned that your dog has a food intolerance, or a food allergy, there is a process you can go through to identify the offending food. The purpose of this process, called an ‘elimination diet’, is to help owners single-out particular food types or groups which may be causing their dog’s digestive discomfort or worse.

As we’ll read, an elimination diet isn’t a complex thing but it’s a slow process and takes dedication and total control of your dog’s environment.

So what exactly is an elimination diet and what does the process involve?

Identify and eliminate

The first step in an elimination diet is to make a list of all the foods you have given your dog before. They will not be eating any of these foods during the diet.

Once you’ve done this, in consultation with your list work to identify one novel protein and one novel carbohydrate source. This will be all your dog eats for the duration of the diet. Put another way, on an elimination diet, your dog will only eat one type of protein and one type carbohydrate that they have never eaten before.

Example of a novel protein which most dogs won’t have eaten before include venison, duck, mackerel, rabbit, kangaroo and pheasant.

To ensure your dog gets enough calories choose a starchy carbohydrate. Care should also be taken to avoid feeding your dog gluten during an elimination diet as it’s a type of protein found in certain grains such as wheat, bulgur and rye.

Gluten free carbohydrate options include potatoes (including sweet potatoes), rice, quinoa or buckwheat.

It’s good to note that there’s an element of trial and error with identifying what these protein and carbohydrate options might be. That is, you may have chosen a novel protein and carbohydrate that your dog hasn’t had before, but it may still cause your dog problems.

If it should happen that your dog develops new symptoms or their symptoms worsen while consuming the novel protein and carbohydrate you first choose, change each of them out one at a time to identify an option that doesn’t cause issues. For example, you would first swap the novel protein source for another, then if the symptoms continue, replace the carbohydrate source with another etc. etc.

Repeat this process as and if necessary until you have identified a novel protein and carbohydrate source that your dog can tolerate. Once this is done, the next step is to only feed your dog these foods for a minimum of 6 weeks, but 8-12 weeks is preferable. No treats, chews or other food of any kind or supplements should be given to your dog during this period of time.

Introducing new ingredients

The elimination diet is not a balanced diet and by now your dog has been on a very restricted diet for maybe a few months. This doesn’t present an immediate problem for a healthy adult dog. Your dog’s body has a storage of nutrients it can draw on if a nutrient is lacking, but it’s time to restore those reserves.

Going forward, the diet should now be balanced according to the NRC guidelines.

Calcium plays a vital role in your dog’s health so this would be my first addition and must be given for a minimum of 4 weeks to note reaction before adding a new ingredient to provide missing nutrients.

If you are unsure how to balance your dog’s diet to meet the NRC nutrient requirements a consultation with a nutritional specialist can provide a balanced diet for your dog.

It’s a slow process, but don’t quit

Elimination diets are time consuming, can last for up to 6 months and you may not see results right away. You may get frustrated at a perceived lack of progress half-way through and want to give up. Don’t! Stick to the plan.

You won’t see a massive change or a big breakthrough overnight, but the long-term benefits to your dog once the offending food type has been identified and they no longer have allergy or intolerance symptoms will be worth it.

On top of this, it should be remembered that a blood, saliva or fur test isn’t accurate enough to diagnose a food allergy or intolerance. So as challenging as they may be, an elimination diet is the only truly effective way to identify the food type that is causing your dog discomfort.

So, some top tips for an elimination diet are: Be patient, stick with it and remain positive.

Meet Patchi

Her owner contacted me because Patchi was suffering from food allergies and had lost her fur around the neck and other parts of her body. Patchi was put through a food elimination diet. Three months on Pathci is no longer scratching and her fur has grown back.


Learn more 

How your dogs immune system can go wrong – Allergies

Dogs and fur stains

Our consultations 

Did you find our blog interesting? Feel free to share by using the super easy share buttons below.