I find that the only knowledge the assistants at the pet food places have is what ever is written on the packaging - if the packet says it's natural premium quality food thats what they tell the unknowing customers. Girl at Petbarn tried to tell me I should buy Eukanuba I replied "really, even though it has by products and corn which of course you would know is known to cause allergies in dogs not to mention that it has beet pulp in it" she froze, smiled and remembered she had another customer to serve - she had no idea what I was on about. The brands I mentioned earlier will not be at your current pet food place. The only places that stock it are Pets Paradise and Pet Goods Direct here is a link that you can find a place near you that stocks it just select the appropriate country
http://www.innovapet.com/international.asp