Pre-heat oven to 350 degrees.
In a medium bowl, whisk together flours and powdered milk.
Add beaten egg, chicken, carrots, parmesan cheese (if using), and ¾ cup chicken broth and mix together until just combined. The dough should be firm, but malleable. If it's too dry, add remaining ¼ cup chicken broth 1 Tbsp at a time.
On a lightly floured surface, knead dough a few times. Roll dough out to a ¼-inch thick round. Cut out cookies using cookie cutter of any shape.
Place cookies on parchment paper-lined baking sheet and bake for about 25-30 minutes, until treats are turning golden around edges.
Let cookies rest in in pan for about 5 minutes before moving to wire racks to cool completely.
Store chicken dog treats in airtight container in the fridge.