Found this site, spent time researching a 5 star option… Merrick… Our 2 yr old yellow lab has been eating a 2.5-3 star IAMs dry food… We feed 1 cup 2x/day… Tonite gave her 1/4 cup new food and 3/4 old… 20 minutes later she left it in our hallway. Any suggestions? Not a smart idea to go from 3 to 5 star? Too much for her system?