Two different types of dog food

The Changing Dog Food Guide

Written By Vedrana Nikolic | Canine Coach, B.A Ethnology & Anthropology, M.A Semiotics.
Edited & Fact Checked By Renae Soppe | B.A Journalism & Science. 
Last Updated: 4th January 2024

Finding the right food for your canine companion often turns out to be more difficult than expected.

First of all, most pet parents want to choose kibble or wet food with the best ingredients possible - but that’s often easier said than done. And once you think you’ve found the perfect formula, it turns out that your dog simply doesn’t like it. Or maybe their poop turns weird. And then you have to look for new food.

Is changing dog food often a good idea? How to switch dog foods in a way that causes the least stress to your dog? This guide covers everything you need to know when switching dog food.

Dry dog food and raw dog food

Switching Dog Food Step By Step

In general, the most common way to switch dog food is by doing it gradually. Even if they are not picky eaters, most dogs will have some sort of reaction to changes in their diet.

While most dogs could certainly deal with a sudden change of food if necessary, it is much more gentle to their gastrointestinal system to change the food slowly. Changing the food suddenly usually results in mild stomach upset but sometimes the symptoms can get more serious. We’ll get into that below, but first, let’s talk about the gradual method for switching dog food.

Basically, the key is to mix old and new food so that the total amount is the same as what your dog is used to. Start with smaller amounts of the new food mixed in with the new one, and gradually increase the amount of new food.

  • Day 1: 75% food your dog is used to, 25% new food
  • Day 3: 50% new; 50% old
  • Day 5: 75% new diet; 25% old diet
  • Day 7: You can start feeding the new food exclusively.

Now, you should keep in mind that this is only a general guideline. It is not necessary to make exactly 25% of new food, for a start, for example. The key is just in mixing the food gradually to ease your dog into the new diet.

Moreover, some dogs might need more time to get used to the new diet than others. If you notice any symptoms of stomach upset (see below) go ahead and slow down the process. For example, you might want to keep the mix at 50/50 for a couple of days longer to see if your canine companion will get used to the new diet (if the symptoms keep getting worse the new food might not be the best choice after all).

Switching Dog Food Too Quickly - Symptoms

When you switch the dog food too fast, you might notice symptoms in your dog that can range from mild to moderately serious. The most common symptoms include:

  • Diarrhea
  • Vomiting
  • Changes in appetite
  • Skin inflammation
  • Loss of hair

Watching the stool is the best way to monitor your dog’s reaction to their new diet. Yes, we know, watching the poop is kind of gross, but it’s something most pet parents get used to over time. After all, our dogs can’t tell us when something is wrong, so we have to watch for signs.

Diarrhea is by far the most common reaction to changes in diet in dogs. If the symptoms are mild, adding probiotics to your canine companion’s diet might be all it takes to fix the issue. In serious cases, you might want to put your dog on a bland diet (rice and chicken only are usually recommended) for a couple of days.

Symptoms like vomiting and changes in appetite can also appear. “Cutaneous symptoms” - those showing up on the skin can also appear in relation to food (1). None of this is a reason to worry if the symptoms disappear quickly, but if any of the symptoms last for more than a week you need to consult with a veterinarian on what to do.

Food Sensitivities And Other Adverse Reactions In Dogs

The gradual approach to switching dog food also gives you an opportunity to detect food sensitivities your dog might have. But first, we should make clear the different reactions to food a dog might have.

Related: Sensitive Stomach Dog Food Review.

‘Adverse reactions to food’ is a term that covers all the problems and reactions a dog might have to any type of food. When switching dog food, temporary symptoms named above are completely normal. However, if the symptoms persist, your dog might have a food intolerance or food allergies.

In general, food intolerance can have similar symptoms to those that appear when switching dog food too fast:

“A food intolerance is different from an allergy in that the symptoms are not caused by an immune reaction. In dogs, food intolerances typically cause tummy troubles; they may vomit or have diarrhea, be seriously gassy, or have a poor appetite.” - Jennifer Coates, DVM, for PetMD

Therefore, if the symptoms persist, the real cause might be intolerance to some ingredient in the new food.

Food allergies, on the other hand, are more likely to show up on the skin - in the form of itchy and irritated skin, loss of hair, and similar symptoms.

Common Reasons To Change Dog Food

Why would you change your dog’s food in the first place? Where in the life of any dog there simply come times where food needs to be changed. Here are some of the most common reasons to change dog food:

Recalls or unavailability of old food in general. Sometimes your dog’s favourite kibble simply disappears from a store in your area. Sometimes there are food recalls when you might be forced to switch to a new food quickly (see below). All of this is completely normal and happens from time to time.

Your dogs stop responding well to the old food. Sometimes, for no apparent reason, dogs start having a mild reaction to their standard diet. This can cause changes in their stool. Sometimes switching to a new dog food is all it takes to make their tummies happy again.

Your dog’s activity levels have changed. Dogs who spend all day chilling in an apartment and dogs who spend all day hiking or working have different needs, of course. When your dog’s habits change there might also come the need to switch to a more (or less) energetic dog food.

Your dog needs to lose (or gain) weight. For example, obesity is especially common in small and tiny dog breeds. Being overweight is not just a cosmetic issue, though, as it can lead to lots of health problems. When your dog keeps gaining weight, the best course of action is to make changes in the food.

Your canine companion is getting old. Senior dogs are often less active and need less caloric and more easily digestible food.

Medical diets. Many diseases in dogs can be treated, at least in part, with appropriate diets. When your dog is suffering from problems like diabetes or heart and kidney issues, for example, your vet might recommend switching to a specialized diet to help treat the disease.

Is The Gradual Approach To Switching Dog Food Always The Best Choice?

While switching dog food gradually is the most common option and one that is most gentle to your dog’s tummy, sometimes a different approach could be taken. Some vets, for example, recommend switching to medical diets immediately when needed to accelerate the effects:

There are times, however, when I do recommend the cold turkey approach. In cases of gastroenteritis, heart failure, kidney disease, some type of bladder stones, canine cognitive dysfunction or food allergies, I will use a prescription diet as I would a medicine because I want the benefits to kick in ASAP.” - Jennifer Coates, DVM for PetMD

In addition to this, dogs sometimes develop food allergies at seemingly random times in their life. When your dog suddenly develops a severe allergy to some ingredient of their food, you’ll also need to switch immediately, for example.

The ‘cold turkey’ approach might be a bit harder to your dog’s stomach and cause upset for a couple of days, but sometimes it’s the best choice overall.

Final Thoughts

As you can see, switching your dog’s food is usually a fairly easy process. However, if you want to make it as easy for your dog as possible, follow our guide and everything should be fine. Good luck!


Is switching dog food too often bad for dogs?

While we, as humans, like to have some variety in our diet, dog’s don’t love that. While it might seem better to offer your dog a varied diet, canines benefit from sticking to the same formula.

That is not to say you should never switch your dog food. You can do that, but it’s best to follow the gradual approach described above. As you can see, that also means it will take at least 2 weeks for your dog to get completely used to the new diet. Therefore, changing dog food too frequently is not the best idea, but once in a while, it’s completely fine.

How long does it take for a dog's stomach to adjust to new food?

For dogs with strong stomachs, the process shouldn’t take more than a week. However, for some canines, it might take two weeks and up to a month to adjust to changes in diet.

What to do if you switch your dog's food too fast?

This depends on the reaction your dog is having. If your canine companion starts vomiting, make sure they have access to plenty of water (as they always should) and don’t feed any food for the rest of the day. In more severe cases of diarrhea, you might want to switch to a bland diet for a couple of days.

  1. “The Right Way to Switch Dog Foods”. July 8, 2019. AKC. Retrieved July 14, 2021.
  2. Coates, J. February 10, 2020. “How to Tell if Your Dog Has Food Allergies”
  3. Coates, J. February 10, 2012. “How to Switch Dog Food”. PetMD. Retrieved July 14, 2021.

Vedrana Nikolic

Vedrana Nikolić is Gentle Dog Trainers Canine Coach, Professional Writer, Anthropologist & dog lover.

With a Masters Degree in Semiotics & Bachelors Degree in Anthropology, studying the communication between animals and humans, Vedrana is able to use her expertise to analyse and review dog products and write informative posts on canine behaviour and training.

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