Cooper also vomited several times when first switched to Canidae. Also had loose stools. He was on antibiotic at the time so I thought it was that, but looks like this may somewhat common. Now he's fine on canidae and has firm poops as well.
On a side note, my wife saw me looking through the forums and saw a picture of Kiah and said, "Please tell me Cooper isn't going to get that big!" I told her he probably would and she was worried until I showed her a picture of Ekim! Now she's REALLY worried about Cooper getting too big. LOL! I told her I'd have Cooper take up smoking to stunt his growth.