If you need to switch the food eaten by your dog or cat, it's important that the switch occur slowly over time and that you don't just start giving them a completely new food right away. Abrupt change in diet for dogs or cats may result in stomach upset, discomfort, or diarrhea. Using a gradually transition from one food to another will greatly reduce the chance of your pet developing an upset stomach as a result of the food change.

To change their food start out by giving them 75% of their existing food mixed in with 25% of the new food. Use this mixture for two days. Then change the mixture to 50% of the old food and 50% of the new food and feed them that for two days. Next change the mixture to 25% of the old food and 75% of the new food and feed them that for two days. After that, you can switch them over to the new food 100%.