Where can I find dog nutritional requirements? Every place I look at has different RDAs for all sorts of nutrients, and nothing to tell you the different requirements between breeds and sizes or for puppies/older dogs as opposed to full grown adults.
You are asking for a huge volume of information. The least biased sources I can find for you are:
Nutrient Requirements of Dogs, Revised 1985, National Academy Press, Washington D.C., 1985 (National Research Council, subcommittee on dog nutrition.)
Nutrient Requirements of Cats, Revised 1986, National Academy Press,
Washington D.C., 1986 (National Research Council, subcommittee on cat
These are all published as books, not as popular websites. Of the eleven highly qualified professionals on these committees, only one was employed by a pet food company.
It’s waltham that’s done the most research in breed specific nutrition, but they make pet food, so that might not have been what you wanted.