All dog foods are required to meet certain nutritional standards, so manufacturers must add certain minimum amounts of vitamins and minerals. Like any other ingredients, these can vary in quality and in how well the body can absorb them. Any other supplements are not a "must" but some of them add considerable health benefits. Certain nutrients are lost or altered during processing, but manufacturers of quality foods take great care to add them back into their product after it has cooled down sufficiently. Do not hesitate to ask if you can't locate the information on the bag, in a brochure or on the internet or have additional questions. Trustworthy companies will gladly inform you about their procedures.
In 2010, enteric fermentation accounted for 43% of the total greenhouse gas emissions from all agricultural activity in the world,  26% of the total greenhouse gas emissions from agricultural activity in the ., and 22% of the total . methane emissions.  The meat from domestically-raised ruminants has a higher carbon equivalent footprint than other meats or vegetarian sources of protein based on a global meta-analysis of lifecycle assessment studies.  Methane production by animals, principally ruminants, is estimated 15-20% global production of methane, unless the animals were hunted in the wild.  
This National Standard of Canada Footnote 1 provides additional information to CAN/CGSB -, Organic production systems — General principles and management standards, in the form of permitted substances to be used as annotated in accordance with the scope of the table in which they are listed. Use of a listed substance in a manner inconsistent with the scope of the table in which it appears is not permitted, except as specified in a listed substance annotation. Listed substances shall comply with prohibitions in of CAN/CGSB -.