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How to change cat food
Pick cat food based on life stage.
The nutritional needs of your cat will change as they grow and age, so you should change their food when they are making a life transition. If your kitten is becoming a cat or your adult cat is becoming a senior, you should choose a food that is appropriate for their new stage of life.
Depending on their health and preferences, you may also want to switch between brands of cat food or between dry and wet varieties of food. Mix the old with the new food.