Preheat oven to 350F
Mix the eggs and sweet potatoes in a large bowl until smooth.
Add the milk and salt and combine well.
Add the flour 1/2 cup at a time mixing well between each. This will make a stiff, somewhat dry dough.
Turn it out onto a lightly floured surface (use the same flour you make the biscuit with) and knead until well combined.
Use a rolling pin to roll the dough to 1/4" - 1/2" thick depending on how thick your pooch likes their biscuit!
Use a knife, cookie-cutter, biscuit cutter, just whatever, depending on what shape you want your biscuit, and cut the dough.
Collect any scraps and shape them into biscuits as well. The size you cut the biscuit determines the number you will get.
Place on a baking sheet - ungreased, unlined - and bake for 20 minutes.
Take them out and carefully turn them over and bake for 20 minutes more.
Remove to a cooling rack and allow to cool completely before feeding them to your dog.