No, adding other ingredients to our recipes is not necessary (except for our base mixes which require protein to be added). All of our complete & balanced foods are formulated to meet the AAFCO Nutrient Profiles and can be fed alone. However, many of our customers love to mix up their companion’s meals with home-made extras. We encourage this because we think pet’s deserve variety in their diets just like we humans do—plus, it introduces more nutrients into their diet, which can lead to better overall health. Our foods have balanced calcium: phosphorus ratios to allow you to add in extras in moderate amounts without throwing these important minerals outside their optimum ratios.