Line dehydrator trays or baking sheets with parchment paper if using an oven.

Slice the liver into strips about 1/4 inch thick, keeping the pieces as uniform in size as possible.

Arrange the liver slices in a single layer on the trays, leaving a little space between each piece so air can circulate.

If using a dehydrator, set it to the meat or jerky setting, usually around 160°F, and place the trays inside.

If using an oven, set it to the lowest temperature, around 170°F, and prop the door open slightly with a wooden spoon to let moisture escape.

Dehydrate the liver for about 6 hours, rotating trays halfway through if needed, until the pieces are completely dry, firm, and slightly leathery with no soft or wet spots.

Remove the trays and let the liver treats cool completely on a rack for at least 30 minutes.

Once cooled, break or cut the liver into small bite-size pieces suitable for your dog and store in an airtight container.