Rice can cause all kinds of difficulties in dogs. The potato and duck doesn't seem to. My dog's entire belly, in between the pads of his feet, and the inside of his ears were constantly infected with yeast. It was miserable trying to find out what was going. After talking with several vets, and trial and error by elimination, we figured out it was the rice they used as filler/binder in the feeds I was using. Even some of the best feeds use it. I couldn't afford the buffalo based feeds, they were just ridiculous, so I tried the potato and duck (I can't remember the brand off hand) and his infection cleared right up. When I found that I could get darn near the same formula for half the price, I was elated. I then talked with my vets again and they said that the potato and duck was probably much easier on his system than the other things like chicken, rice, etc. and to keep feeding it. He also did well on an oatmeal based, rather than rice based, but after a while they decided to add in rice, go figure.
I would say give it a shot. My mom's dog is an obnoxious dachsund who has an incredibly sensitive stomach. I got her started on it and she hasn't vomited once since. With her, it was an every day, almost every time she ate kind of thing. She had to be fed almost double to make up for the vomiting while we tried to figure out what to do. The duck and potato took care of it.
