How Long Will My Dog Have Diarrhea After Changing Food?

How Long Will My Dog Have Diarrhea After Changing Food
Spread the love

Switching your dog’s food is sometimes necessary, or sometimes it might just be time to change things up. That said, changing your dog’s food will probably cause some degree of diarrhea, just so you are prepared. This is normal, and it should not last for too long. Let’s take a closer look at this issue.

The Cause of Diarrhea 

It is well known that changing dog food can and does cause diarrhea, quite often in fact. The reason for this is actually quite simple, and it’s usually nothing too serious. Simply put, your dog is used to eating one kind of food with very specific ingredients. If you keep feeding your dog the same food for months or even years, the dog’s stomach and intestinal tract gets used to that food.

When you switch foods, it’s like a shock to the system. Your dog’s digestive tract and stomach is not ready for the new food. It’s a really fast change, and this is what causes the upset stomach. It has to do partially with the bacteria in your dog’s stomach.

The bacteria in there are equipped to break down the specific food the dog has been eating, but then when you switch the food, those bacteria need to adjust, and new bacteria need to form, which can then handle that new dog food.

In some cases, it may not be the actual switching of the dog food that causes the diarrhea, vomiting, gassiness, and upset stomach, but the new food itself. Dogs, just like humans, can have food allergies and sensitives.

Maybe the new dog food contains an ingredients which your pup cannot handle. Below, we will discuss how long the upset stomach and diarrhea should last, but that said, if it does not subside in a week at most, it’s probably not the switch, but the food itself, in which case, you will have to switch foods again, and yes, probably deal with some more upset stomach too.

How Long Will My Dog Have Diarrhea After Changing Food

How Long Will It Last?

Generally speaking, the diarrhea from switching foods should not last longer than 3 or 4 days at the very most. In some cases it may take up a full week for some dogs to adjust to the new food, but that is really pushing it. For the most part, dogs will adjust to their new food in 2 or 3 days.

If you are switching foods because your dog was always sick on the old food, and it still does not change with new food, you should take your dog to the vet to get examined.

In any case, if the diarrhea lasts for more than a week in any case, go see a vet, as your dog may have a food sensitivity, the new dog food may not be ideal, or your dog may have some other illness which is causing the upset stomach.

How to Properly Switch Dog Food

All of that said, there are right ways and wrong ways to switch your dog’s food, and some good tips to follow. One thing we need to talk about is switching foods ‘cold turkey.’

As we will soon discuss, switching dog food cold turkey is about the worst way to go about it, but in some cases it may be your only option. Your dog may need new food due to sensitivities, or the old food may have been discontinued.

Here are some tips to follow if you have to cold turkey switch your dog’s food.

  • Get your dog to fast for a day, or in other words, don’t feed them for a full day before introducing the new food into its diet
  • Only feed your dog half of what you would normally give them on the first day, then 75% of its regular portion on the next day. Introducing only small amounts of new food may help to prevent or reduce the diarrhea
  • Adding digestive aids like pumpkin (the fiber is great for digestion) or probiotic bacteria can go a long way in easing the transition

The Right Way to Switch Foods

The best way to switch dog food is by doing so gradually, so it is something that takes a bit of planning.

Ideally, for the first 5 to 7 days, mix only 25% of the new food with 75% of the old food. In the second week, change the ratio to 50/50. 

Then in the third week, change the ratio to 25% old food and 75% new food. Then, finally, after about three weeks, you can give your dog only the new food. Also, adding some digestive aids also helps.


There you have it — just switch the dog food slowly and it should all be fine. Yes, your dog will still probably experience some diarrhea, at least for a couple days, but if you do it right, you can avoid as much of the mess as possible.