Nambroth, that is it exactly - the long term health effects. You know, when you are young (and your animals are young), you can tolerate a lot of stuff: junk food, spicy food, rich food, a date with Jack Daniels, a face plant off the back of your favorite horse, and so on. I am/was healthy but those things aren't healthy for you! When you get a bit older, it affects you a lot more. My dog was soooo healthy looking as a young dog. But in her middle ages, all that inflammation set in and the scratching. Experimenting around with her food made a huge difference. It literally restored some of her youth. The sad part about owning a wonderful dog is that they just don't live very long, especially larger ones. I feel confident that feeding her non-Purina food is going to extend her life and I wonder how much longer she would last and what the quality would be if I'd had her on this kind of food since she was a puppy. I'll never know. But I wish I'd started it sooner.
So my question is, with all the FACTS coming out about dog's intolerance to various grains and to beef, why doesn't Purina make a dog food that doesn't have those ingredients? You know, if they spend soooo much money on researching nutrition and are soooo scientific and all?