Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

How to gradually transition cat food for a diet trial or IBD symptoms?

Updated On September 23rd, 2025

Pet's info: Cat | Mixed Breed | Female | spayed | 13 years old | 6 lbs

My cat (13yr) lost lots of weight (now 6#), eats tons, has loose stool, and vomits occasionally but not often. A vet found no masses, and blood and urine panels came back clean. Now I suspect IBD and want to try a food trial. The instructions on this peteducation.com website for a 12wk trial don't mention easing in or out of a trial, but I thought changing food abruptly causes GI problems, which is exactly what I'm seeking to eliminate with the trial. Should food trials be eased in and out of?

2 Answers

Most Helpful Answer

Image profile

Answered By Lauren Kennedy, DVM

Veterinarian

Published on January 30th, 2018

Yes, it is always good to gradually change over to a new diet rather than doing it abruptly. I usually recommend a period of about 5-7 days to switch food. Start with 25% new food, 75% old food for 2-3 days, then increase the ration to 50:50 for a few days, then further increase it to 75% new, 25% old for a few days, then 100% new food. I hope the diet change does the trick for Z. Best of luck. Let us know if you have any additional questions!

Vote icon

1Pet Parents found this answer helpful

Other Answers

  • Image profile

    Answered By Sarah Box, BVSc

    Veterinarian

    Published on

    Poor Z-it sounds like she has a lot going on!! Did your vet check her thyroid hormone level? Hyperthyroidism is common in older cats and can definitely cause some of the signs you have been seeing. Regarding your question for transitioning to a new diet: yes-ideally you would spend 7-10 days transitioning to a new food. Start by mixing just a small amount of the new food in with the old food you offer her. By about day 5 you would expect to be at a 50:50 mix and by day 10 completely transitioned to the new diet. Be sure and discuss your concerns for IBD with your Vet before starting a diet trial-your Vet may have some additional recommendations and may even offer some diet ideas for you to try that may be most suitable.

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Health & Wellbeing
Why is my mouse's eye swollen, cloudy, and has pus?
Is your mouse's eye swollen, cloudy, and pussy? Dr. Melanie, a certified vet, discusses severe eye issues like infection or abscess, urging an immediate visit.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
What fish dog food helps dry skin if my dog eats Science Diet?
Is your dog's dry skin a concern? A certified vet offers expert advice on finding the best fish-based dog food alternatives to Science Diet for essential oils.
Updated on February 04, 2026
Petco Pet Education Center
Food & Nutrition
What's the best way to feed my hamster when I'm going on a trip?
Planning a trip to Chicago and need to feed your Syrian hamster? A certified vet offers expert advice on feeding options for short and long trips, plus finding trusted pet sitters.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
Can chickens eat bell peppers daily and what about veggie salads?
Can your chickens eat bell peppers and salads? Veterinarian Dr. Elizabeth offers expert advice on safe feeding, frequency, and how fresh veggies boost vibrant yolks.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
Is Purina Layer Pellets good for chickens? What other feeds exist?
Is Purina Layer Pellets the right choice for your flock? Get expert advice from a Petco veterinarian on Purina and other top chicken feed brands for your chickens.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
My newly adopted pet won't eat hay. What can I do to encourage it?
Adopted a pet not eating hay? Dr. Stafford, a certified vet, offers expert guidance on encouraging hay consumption, including adjusting pellets and trying fresh types.
Updated on December 04, 2025
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored