How do I switch my cat’s food without upsetting her stomach?
Transition over 7 to 10 days, slower if her stomach is sensitive. The standard ramp: days 1-3, mostly the old food with a small portion new; days 4-6, half and half; days 7-9, mostly new with a bit of old; day 10 onward, all new. Mix the two at every meal rather than alternating whole meals, and use the same total portion size. Sudden switches cause vomiting and loose stools in cats more reliably than almost anything else. For cats with a history of GI issues, a 2 to 3 week transition is worth the extra patience.
When to call a vet: if vomiting or diarrhea persists through the transition or gets worse, stop, return to the old food and call your vet.
