I love the Vital Cat Food formula. Our cat Gracie, age 18 years, has been a picky eater all her life. In the past year, she has had some health problems and lost weight due to age. I started feeding her your cat food about 4 months ago. There was no "transition period" needed...Gracie went for the food right away, and eats it all up every time. Her digestion is better, she seems more healthy and energetic, and has even gained 2 lbs. of weight back. I now feed our two younger cats the Vital too. Thanks for making such a high quality product. We can see the difference this food makes in our cats and I'm so glad to have found a premium brand of food that they actually love to eat!