Place all ingredients in a large stock pot, cover with 4 inches of water, bring to a boil, reduce the heat and boil for 2 hours.
Strain the solids from the broth and save for dog food.
To preserve the stock for later use you can freeze or can.
Option 1: Freeze - Simply let the broth cool and ladle into freezer containers.
Option 2: Pressure canning - Prepare pressure canner, jars and lids 30 min before stock is finished. Ladle hot stock into hot jars leaving a 1″ head space. Screw on lid and band. Place jars in pressure canner. Adjust water level, lock lid and bring to a boil over medium heat. Vent steam for 10 min then close vent. Continue heating to achieve 10lbs pressure. Process for 25 min. Turn off heat. Let pressure return to 0. Open vent and remove lid. Wait 10 min then remove jars.