I just thought I would chime in here on the vets don't know anything about nutrition topic. I'm a registered dietitian (for people obviously

) and to tell you the truth, doctors don't know anything about human nutrition either!! MDs too get very little training in nutrition, maybe an afternoon seminar and that's really it. Unless a doctor takes a particular interest in nutrition, they are really quite useless in this area. It seems as though it's similar for vets too.
I feed my boxer Canidae. When my vet asked what I was feeding him, she said she had never heard of it. I had told her that when we first adopted Ricky the vet recommended ProPlan and he loved it. But, I had done some research and found that ProPlan wasn't very good at all and Canidae is a very high quality choice. She said "Is this site put out by the Canidae people?" I explained that no it wasn't and it goes over the ingredients one by one and pros/cons etc of many, many foods. I told her that I liked the fact there is no corn, by-products, soy etc. Her reply was (I swear I'm not making this up) "I don't have a problem with by-products or corn. I eat corn, I like it, it tastes good." HELLO....you're not a dog.....
Then, get this, when I told her that I am a dietitian so I do take a particular interest in what he eats. She said "Oh boy did he get the wrong person to adopt him!!" Do you believe that!!?!? I replied "Or the right one!" I couldn't believe she said all those things.
I think I'll ask for a different vet next time. I'm dying to hear from the original poster as to what their vet said after reading the ingredients for CS.