How to switch cat food: transition planner
Knowing how to switch cat food slowly is the best way to avoid an upset stomach. Pick a start date and a plan length, and this cat food transition planner builds a day-by-day schedule for mixing old and new food.
Free calculator · Based on vet sources
| Day | Date | Old food | New food |
|---|
The standard cat food transition schedule
Most cats do well with a 7-day switch: 75% old and 25% new food on days 1 and 2, half and half on days 3 and 4, 25% old and 75% new on days 5 and 6, then all new food on day 7. Longer plans keep the same four steps and just spend more days on each. Mix the two foods well in the same bowl so your cat can’t pick out the old one.
Signs it’s going well
- Your cat eats each meal with normal interest.
- Stool stays formed and about the same as usual.
- No vomiting, and your cat is as active as normal.
Upset stomach: when to slow down
Go back to the last step your cat handled well and stay there for a few extra days if you see:
- Soft stool or mild diarrhea
- Vomiting
- Refusing food or eating much less than usual
Call your vet if diarrhea or vomiting lasts more than a day or two, if there’s blood, or if your cat seems unwell.
Never let your cat go without eating while you switch
It’s better for your cat to eat the old food than nothing. A cat that eats nothing for more than 24 hours needs a vet, because cats that stop eating can develop hepatic lipidosis (fatty liver disease), a serious condition. See cat not eating.
Tips for mixing old and new food
- Keep the total amount the same. You’re replacing part of the old food, not adding extra.
- New food may have more or fewer calories. Check portions with the cat calorie calculator.
- Switching from dry to wet food? Warm wet food slightly to body temperature; many cats like the smell more.
- Keep feeding times and the bowl the same so only one thing changes.
Questions about switching cat food
How long should it take to switch cat food?
About 7 days for most cats. Take 10 to 14 days if your cat has a sensitive stomach or is a picky eater, and only switch faster if your vet tells you to.
Can I switch cat food without mixing?
A sudden switch can cause vomiting, diarrhea or a cat that refuses to eat. Mixing old and new food over a week gives your cat’s gut time to adjust. If your vet prescribes a diet that must start right away, follow their plan.
What if my cat won’t eat the new food?
Go back to the last mix your cat ate well and move more slowly. Never let your cat go without food to force the change. A cat that eats nothing for more than 24 hours needs a vet.
Is diarrhea normal when changing cat food?
Slightly softer stool for a day can happen. Diarrhea that lasts more than a day or two, blood in the stool, vomiting or lethargy means you should stop the switch and call your vet.
Source: general feeding guidance from the Cornell Feline Health Center and International Cat Care. If your cat is on a prescription diet or has a medical condition, follow your vet’s plan.
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