How to switch your dog's or cat's food: transition schedule
Switch over about 7 days: roughly 25% new food on days 1 and 2, 50% on days 3 and 4, 75% on days 5 and 6, and all new food on day 7. Pets with sensitive stomachs do better over 10 to 14 days.
Free, no sign-up · Reviewed October 2026 · How it works
How fast?
Choose 10 or 14 days for sensitive stomachs, puppies and seniors.
Keep the total the same; only the mix changes.
| Day | Mix | Old food | New food |
|---|---|---|---|
| Day 1 | 75% old · 25% new | 1.5 cups | 0.5 cups |
| Day 2 | 75% old · 25% new | 1.5 cups | 0.5 cups |
| Day 3 | 50% old · 50% new | 1 cups | 1 cups |
| Day 4 | 50% old · 50% new | 1 cups | 1 cups |
| Day 5 | 25% old · 75% new | 0.5 cups | 1.5 cups |
| Day 6 | 25% old · 75% new | 0.5 cups | 1.5 cups |
| Day 7 | 0% old · 100% new | 0 cups | 2 cups |
If your pet gets loose stools or vomits, go back to the previous day's mix for 2 to 3 days before moving on. Call your vet if it lasts more than a day or two, or if there's blood or lethargy. If the new food has a different calorie content, check the daily amount with our feeding calculator.
How this tool works
Enter how much your pet eats a day and choose a 7, 10 or 14-day plan. The calculator splits that daily amount between old and new food for each day, following the common 25/50/75% steps that pet food makers and vets recommend, or smaller steps for the slower plans.
Keep the total the same during the switch, unless the new food has a different calorie content, in which case adjust the final amount with our feeding calculator.
Questions.
Can I switch dog food without mixing?
It's better not to. A sudden change often causes vomiting or diarrhoea. If you have to (for example, after a recall), feed small, frequent meals and watch the stools.
How long does it take a dog to adjust to new food?
Most dogs adjust within the 7 to 10 days of a gradual switch. Some take a few weeks for their stools to settle completely.
What if my dog gets diarrhoea when switching food?
Go back to the previous day's mix for 2 to 3 days, then continue more slowly. Call your vet if it lasts more than a day or two, or if there's blood, vomiting or lethargy.
Related tools
- How much should I feed my dog or cat?Get daily cups or grams for your dog or cat from their weight, life stage and the calories in your food, plus the amount per meal.
- Dog and cat calorie calculatorHow many calories does your dog or cat need a day? Enter weight and life stage to get daily kcal using the vet RER formula and AAHA life stage factors.
- Raw dog food calculatorHow much raw food to feed your dog or puppy a day, split into muscle meat, bone, liver and other organ.
- Can my dog or cat eat this? Toxic food checkerCheck over 50 common foods: which are safe, which need care and which are toxic to dogs and cats, from chocolate and grapes to cheese and peanut butter.
Read next
