Knowledge is Hill's first ingredient ,and Hill's understands what dogs and cats need to live a long and healthy life, which is why all Hill's foods provide precisely balanced, high quality nutrition based on pets' age and unique needs. Science has driven the creation of Hill's foods since 1939, and today Hill's dog and cat foods are still created using the combined expertise of over 220 vets, scientists, and pet nutritionists. Hill's believes that fed every day with the right nutrition makes, little transformations can add up to incredible results.