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My dog's new food caused diarrhea. Can I switch to another food now?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Female | unspayed | 1 year old | 16.6 lbs

I recently switched my dog to a new dog food, and ever since her poop has been squishy and green and she isn't that interested in eating the food. I got a new food to try since that one didn't go well. However, I do not want her on this old food any longer because of how much it is upsetting her stomach. Is it ok to just switch straight to the new food? I don't have the ingredients here to try a bland diet first. Both foods are dry foods.

4 Answers

Most Helpful Answer

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Answered By Ann Dion, DVM

Veterinarian

Published on December 2nd, 2018

Hello and welcome to Petco Pet Education Center, formerly Petcoach. Usually we recommend a switch to a new food slowly to avoid the signs that you are seeing now (diarrhea, upset stomach, etc.). If you are already seeing these signs then there is no point on a slow switch. I would suggest switching over to the new food now. Be prepared for more diarrhea/upset stomach however, and if you can go buy some boneless skinless chicken breasts and rice, and boil BOTH of these, and feed this for a few days once you get it, it might help. Then mix in the new food slowly. In the mean-time though, just switch to the new food. Best of luck with Aspen!

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1Pet Parents found this answer helpful

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    Answered By Jenna Beyer, DVM, MBA, cVMA

    Veterinarian, Certified Veterinary Acupuncturist

    Published on

    Some dogs are ok with sudden changes in diet. It probably won't cause any more issues than she already has. Try the new food and stick with it for a few days. If she is still having issues with it, I would recommend that you have her examined by a vet. The vet may do an intestinal parasite screening. They can also prescribe probiotics to help with the diarrhea.

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    Answered By Jenna Beyer, DVM, MBA, cVMA

    Veterinarian, Certified Veterinary Acupuncturist

    Published on October 7th, 2017

    When switching to a new food, I recommend that you mix it slowly into the old food over 2-3 weeks. So, for example, the first 5 days feed 75% old food, and 25% new food. The next 5 days feed 50/50. The next 5 days 75% new food and 25% old food. If you see nausea, vomiting, or diarrhea during any of this period, then back off and transition a little slower. If the symptoms continue, then your pet may have a dietary intolerance to the new food and it should not be used.

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    Answered By Christie Long, DVM

    Veterinarian, Certified Veterinary Acupuncturist

    Published on November 7th, 2018

    In order to minimize the chance of developing digestive problems, dogs should be fed a consistent high quality, complete and balanced diet. This includes feeding the same diet from day to day. If a change in diet is needed, it should be made gradually by mixing the old and new foods together over 5-7 days. Feed 75% of the old food with 25% of the new food for a day or two, then 50% of each for another few days, and then 25% of the old food with 75% of the new food for another day or two before exclusively feeding the new diet. Never feed table scraps. Sudden diet changes or new foods can commonly result in an upset stomach with vomiting and/or diarrhea.

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    41Pet Parents found this answer helpful

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