While it’s perfectly safe to stop feeding your cat’s previous food one day and introduce Fussie Cat the next, we recommend a gradual transition to Fussie Cat for up to two weeks. This is especially true if your cat has been previously fed a high grain, corn, wheat or soy diet. Start by introducing a small amount of Fussie Cat, increasing it daily while decreasing the previous food by the same amount. This will help avoid upset stomachs as it makes it easier for your pet’s digestive system to acclimate.