We recommend at least a 7 day transition before you begin feeding the new food exclusively. Start by mixing 75% of the old diet with 25% of the new diet on Day 1 and Day 2. On Day 3 and Day 4, mix 50% of the old diet with 50% of the new diet. On Day 5 and Day 6, mix 25% of the old diet with 75% of the new diet. On the 7th day, you can feed the new food exclusively. This allows your pet's digestive system to smoothly adapt to the new food.