How to Introduce a New Food to Your Pet

Last updated on 25 OCT 2018

This article is written by one of our in-house veterinarians, Dr Teagan Lever BVSc.


There can be a number of reasons why you may need to change your pet's food. They may have graduated from puppyhood to adulthood; or perhaps they have developed a medical condition requiring special food. Whatever the reason, to avoid tummy upsets or having them turn their nose up at the food there are a few basic rules to follow.


Introduce it Gradually

To save your pet from developing diarrhoea and flatulence, introduce the new food gradually over a period of one to two weeks. This means planning ahead and buying a bag of the new food before the old one runs out!

Nutritionists worldwide recommend a gradual change when swapping your pet over to a new food. The main reason for this is to avoid gastrointestinal upsets. Cats and dogs are prone to diarrhoea and occasional vomiting when their diet changes, especially if they've been on the one food for a while.

You may be lucky and have a pet with an iron gut, who won't show any signs of a tummy upset with a quick change of food. Your pet is also less likely to react if you are making benign change, such as swapping from a chicken-based dry food to a beef-based dry food of the same brand. However, most people prefer not to take the risk, as diarrhoea on the carpet is never fun to clean up!

Most sources you read will recommend a 'gradual' change, and when googling the topic, you might notice there are a wealth of different methods recommended by different sources. So long as the time period allowed is gradual, there's not really any wrong 'method' and you might find that a different method suits you and your pet. However, after thoroughly reading up on the topic, we have based our recommendation on that made by nutritionists from both Hill's and Royal Canin due to their heavy backing of research into animal nutrition science.


Here's what we recommend:

Day 1-2: Mix 25% of the new food with 75% of the old food

Day 3-4: Mix 50% of the new food with 50% of the old food

Day 5-6: Mix 75% of the new food with 25% of the old food

Day 7 onwards: 100% new food

Make it Appealing

It's not uncommon for picky eaters to turn their nose up at something they haven't encountered before. If the gradual introduction is not enough to trick your fussy pet into eating his new diet, you can try and increase its appeal by using their sense of smell. You can do this by mixing kibble with warm water, or heating it in a microwave for a quick burst. Just make sure that the food is not so hot that it will burn your pet's mouth as this is likely to put them off for good!


Don't Give In

Don't fret if your pet decides they would rather go hungry than eat their new food. For a healthy cat or dog, skipping a meal will not cause any harm. If you give in immediately your pet will quickly learn that they have you wrapped around their little finger and will keep on holding out for the good stuff! In most cases if you don't give in, it's likely that by the next mealtime they will be hungry enough to give the new food a go. If your pet refuses more than two meals in a row, you may need to consider offering an alternative diet.


When introducing a new diet to your pet, it's important to take things slowly for a smooth transition. It is not uncommon for dogs and cats to develop transient diarrhoea or flatulence despite the best laid plans, but this should resolve within a few days. If your pet has persistent diarrhoea or will not eat, you should contact your veterinarian for further advice.