Place tuna, rice and oat flour, eggs, pumpkin, cinnamon, and feta in the food processor.
Process the mixture until smooth.
Line an 8 inch x 8 inch baking pan with waxed paper. You use a greased pan as well, but using waxed paper makes it a little easier to remove the treats from the pan and saves some clean up time.
Spread the tuna batter in the pan.
Place pan in the oven and bake from about 15 minutes, until a toothpick you put in the fudge comes out clean.
Let the fudge cool in the pan for 5 - 10 minutes before removing it and placing on a cutting board.
Cut the fudge in small cubes.
Stored in a sealed container, these will keep for a week in the refrigerator, longer in the freezer.
Notes
Give you canine friend some variety. Substitute 1/2 banana for the pumpkin, canned chicken for the tuna, or parmesan cheese for the feta. Be creative and find your own favorite combination.