Is it normal for my dog to have diarrhea after changing food? A Step-by-Step Guide

What is Diarrhea Due to Diet?

There are instances when your dog will suffer from bouts of loose stools or diarrhea. Often, diarrhea will be the result of an illness but there are also instances when diarrhea is caused by your dog’s diet. This can be from eating too much, eating spoiled food or eating out of the garbage. A food intolerance or allergy can also cause your dog to experience diarrhea.

Changing your dog’s diet can also cause your dog to develop diarrhea. When you change your dog’s food it can take a few days for your dog’s digestive system to fully adapt to the new food. It is recommended that you slowly change your dog’s food from one source to another by mixing the two together equally and then slowly decrease the amount of the first food.

When your dog eats, the food will travel down the esophagus quickly and enter the stomach in large pieces or chunks. Their salivary enzymes are not designed to break down the food but to kill bacteria. The acids within the stomach will break down the food, disperse the nutrients and rid the body of waste in the form of well-formed stool and urine.Youtube Play

My dog has diarrhea after changing her food. How is this treated?

Most cases of diarrhea due to sudden diet changes can easily be corrected by changing back to the diet the dog has been used to. As mentioned above, adverse food reaction during diet change happens when the digestive enzymes in the dog’s gastrointestinal system cannot fully process the components in the new diet, resulting in diarrhea and vomiting. Changing back to the old food where innate enzymes can easily digest will help control signs associated with the adverse food reaction.

In cases with severe symptoms, medical management such as antidiarrheals and anti-emetics may be needed to fully control the gastrointestinal disturbance. Severe cases can predispose the intestinal tract to secondary infection and the proliferation of pathogenic and opportunistic bacteria requiring antibacterial therapy to treat.

Most cases respond well to treatment and changing back to the previous diet, with signs resolving in 24-48 hours after the start of treatment. If left untreated, the continuous inflammation along the intestinal lining may lead to more serious health conditions.

Causes of Diarrhea Due to Diet in Dogs

Diarrhea can occur for many different reasons in dogs. Commonly it is illness that causes your dog to develop diarrhea. However, diarrhea due to diet should not be ruled out. Many times your dog will get into something that they should not have eaten and that can cause stomach upset and diarrhea.

Changing your dog’s food can cause diarrhea if not done slowly so their digestive tract can adjust to the new food. Allowing your dog to eat too much or eating garbage can also cause diarrhea. A food allergy or intolerance can cause gastrointestinal upset and diarrhea.


So, you switched your dog’s food to a fresh food diet to give them a healthier and happier life. Great work.

That said, dietary changes of any type can cause temporary digestive distress to your dog, even when you’re switching to a healthier option. The good news is that with an appropriate transition and some patience, your dog will be over the hump in no time.