I have 11 dogs (6 borzoi, 2 greyhounds, 2 dachshunds and a saluki) and started feeding Natural Balance about a year ago when I adopted a greyhound who had a very sensitive tummy and could not tolerate other brands, which I was feeding prior. Amazing things happened after this switch. Diarrhea went away in the greyhound, 2 of my other dogs gained weight and maintained their new health weight. Everyone's coat is beautiful! I feed a mixed variety of Natural Balance, a mix of rabbit, duck, chicken, lamb, venison, bison and synergy. I found this way kept everyone happy and interested...having 11 dogs and fosters coming through my doors often some did not care for certain "flavors" so I started mixing the 4-5 bags of different formulas together. My lure coursing borzoi and greyhound have a lot more energy and stamina! We have maintained muscle mass, weight, build up RBCs. Have sent other feeders to Natural Balance due to sensitive tummies and unhappiness of the previous product and they love Natural Balance!