I work at a pet food store and I know that some dog food companies do have special deals for breeders. Pro plan is one that gives a lot of perks. Their food isn’t that great, but it is a step up from SD. Acana/Orijin has a deal where breeders buy 5 they get one free. They might offer something similar for rescue groups. Otherwise try talking directly to your local pet store owner, especially a smaller independent store. Ask if they will sell to you for cost, plus 10%. We do that for a local rescue with kitten formula. If you offer to direct new pet owners to that store for their pet supplies, it is a win/win situation.
Good luck!
