To assure that your older dog is getting all of the vitamins and minerals he needs, you might consider adding some human grade bonemeal and a few drops of a vitamin supplement to the food you make for him. (dogcare.dailypuppy.com)
Bonemeal powder or calcium citrate (a source of calcium) must be provided when feeding meat to prevent a calcium deficiency (foundersvet.com)
✓ Large and giant breed growth: Add 8 g of typical bonemeal to meet FEDIAF standards, or 44 g to this recipe. (darwinspet.com)