Freeze the livers or kidneys for an hour before cutting to make handling them easier. As the treats are frozen, the size of your dog will dictate what size you can cut the kidney or liver into.
Cut the lamb liver or kidney into bite size pieces, then arrange on the parchment on a baking sheet sprayed with non-stick spray, or on a silicon baking mat.
Make sure the pieces of liver and kidney don’t touch each other, as they’ll stick after freezing. After 6 hours, transfer the frozen kidney and liver pieces to a freezer bag and seal.
Give out the treats as a supplement with their normal food, or straight from the freezer as a snack if the dog is large enough to eat them whole, and not drop them on the floor, which can get messy.
If a dehydrator is available, or dried treats are preferred for easy storage, cut the kidney, liver or heart into pieces and dehydrate at 145 F or higher until cracker dry, about 24 hours, or bake on the lowest possible setting in the oven with the door ajar until completely cooked and dried, then store in a covered container at room temperature.
Notes
Depending on the size of your dog, and their eating habits, you may want to cut the meat smaller or larger, depending on your preference.