I can speak from experience on this one! I haven't read the replies...but I actually went to vet school (Kansas State University College of Vet Med) for a year (I had A's and B's...I just hated school too much to go back) and I took the ONE hour ONE semester long course on nutrtition that veterinarians get...and it is sponsored by Science Diet (the text book is made by Hill's...). Science Diet, Purina, and Iams/Eukanuba also give vet students extremely cheap/free food...so that is why many vets will recommend those foods...unless they've done research themselves, which most haven't, all they know is what they learned in that one hour, one semester course sponsored by Science Diet. So, PLEASE don't always trust any old vet on nutrition...