what to feed my 6 mo female doberman

Question
I have had my doberman since she was 3 month old. I put her on Beneful Puppy and it have her horrible gas. So I bought her veterinarian formula large breed puppy and it was obviously much too rich for her. It contains a high percentage of crude protien (26%). It has no corn, by-products, meat, or artificial preservatives. But it has chelated minerals, yeast and rice, flax, omega 3/6, vitamins, eggs, glucossmine, and a few other things. The problem I have is that I feel it might be too rich for her. I tried weaning her onto it and it gave her horrible diarrhea. So I switched her back to beneful and then a few weeks ago weaned her onto purina which makes her break out in what seems to be hives or bumps all over her back. I've heard purina isn't good food, as well as grocery store brands. She is very active and has a beautiful coat (I give her fish oil capsules with her food). I'm just wondering if I should still try the Vets formula brand, or something else. Any info would be greatly appreciated.

Answer
You are in Canada, there is a couple great brands of food made in Alberta I believe, they are also sold in the US, company is Champion Pet foods, brands are Acana and Orijen.  They make a large breed puppy food.   http://www.championpetfoods.com/

Another place to find reviews and ratings of pretty much every dog food, is www.dogfoodanalysis.com  might also want to give probiotics and enzymes to help digestion, several products sold for dogs, such as Nzymes.

Ditch the Purina, it's garbage.  Also look into a raw diet, www.rawfeeding.com or 100 other websites about it, the most natural diet.