How to Switch Your Animal's Food Without Upsetting Their Stomach
A sudden change of food is a common cause of vomiting and diarrhoea. A gradual transition avoids most problems.
Whether you are moving to a new brand, a different life-stage formula or a diet your vet recommended, the way you switch matters as much as the food itself.
A simple 7 to 10 day plan
- Days 1-2: about one quarter new food, three quarters old food.
- Days 3-4: half and half.
- Days 5-6: three quarters new, one quarter old.
- Day 7 onward: all new food.
If your animal has a sensitive stomach, stretch each stage over a few more days.
Tips for a smooth change
- Keep meal times and portion sizes consistent during the switch.
- Avoid adding new treats at the same time, so you know what caused any upset.
- Cats can be very particular about texture and smell. Warming wet food slightly can help.
- Note your animal's appetite, stool quality and energy level each day.
When a gradual switch isn't possible
Sometimes a vet prescribes a therapeutic diet that should start straight away. In that case, follow your vet's instructions exactly - they will tell you how to manage the change.
When to call the vet
Mild, soft stools for a day or two can happen. Repeated vomiting, diarrhoea lasting more than a day, blood in the stool, or a cat that refuses food for more than a day all need a vet check. A cat that stops eating can become seriously ill quickly, so don't try to "wait it out".