here's one that does cats, dogs and horses!! and people can eat them too
4 cups assorted of the following:
whole wheat flour
rolled oats
bran
buckwheat grouts
kibbled rye
1 cup skim milk powder
2-4 eggs to suit
1/2 cup kelp powder
1/2 cup dolomite
water to mix to firm dough
mix all together and roll out to desired thickness. Cut into squares and cook 150-200 degrees celcius (sorry, you will need to convert to f/height) cook until dried to the degree you want
For cats simply crumble the mix