NUTRITION TENDS TO BE an overlooked subject among pet owners since so many people feed their pets a commercial diet. After all, what could be easier than opening up a bag of doggie crunchies and pouring it for your dog? But all dog food is not the same. Depending on what you're feeding your rottie, you may not be supplying him with the right nutrients. Without proper nutrition, your puppy will not grow up to be strong and healthy. If he doesn't get good nutrition as an adult, he will have a dull coat, a poor immune system, and other health problems. If he is a competition dog, that translates into poor performance. If he is a pet, that may mean bigger vet bills and a shorter lifespan.