It's easy to make your own dog biscuits! Try this recipe from King Arthur flour, contributed by Elaine Aukstikalnis, who works in a veterinary office; she regularly brings these biscuits in for their patients--you could say that they've been 'vetted' for flavor!
2 C. white or regular whole wheat flour (you could also use a gluten-free flour)
1 C. rolled oats, regular or quick
1 T. dried parsley or 2 T. chopped fresh parsley
1/2 cup dry milk, any kind
1/2 tsp. salt
2 large eggs
1 C. peanut butter, crunchy or plain
1/2 C. + 1 T. cold water, or enough to make a cohesive dough
Preheat oven to 300°F. Lightly grease baking sheets, or use parchment. Mix dry ingredients together and then add the eggs and peanut butter. Combine until the mixture is crumbly, then add enough water to bring the dough together. Roll the dough 1/4" thick, and cut biscuits with desired cutter. Gather and re-roll scraps until you've used all the dough. To make dog cookies, drop the dough in walnut-sized balls onto baking sheets, and flatten to about 1/4". Bake biscuits for 40-60 minutes, baking the smaller cookies for less time. Finished biscuits will be dark golden brown, dry and crisp all the way through. Remove from the oven, and cool on the pans. Yield: about 42 larger biscuits, 60 smaller biscuits.