Transitioning to a new environment can be a stressful time for your new cat. It is recommended that you continue the same diet your cat received in foster care to prevent potential stomach issues such as vomiting and diarrhea. After your new cat has adjusted to their new environment, if you wish to switch your cat’s diet to a different food, it is recommended to gradually decrease the amount of current cat food while increasing the amount of new cat food over a period of 7 days.