Feline Fish Balls

1 (8 ounce) can tuna in oil, drained
2 ounces cooked herring, skin removed
3 baby carrots, boiled until tender, mashed
1 egg, beaten
3 tablespoons grated cheese
2 tablespoons whole grain bread crumbs or rolled oats
2 tablespoons tomato paste
2 teaspoons brewer's yeast *
1/4 teaspoon catnip

Combine all ingredients; mix well. Roll dough into 1-inch balls and place balls 1 inch apart on a greased cookie sheet. Bake in a 350 degree F oven for 15-20 minutes, until golden brown and firm. Let cool on wire racks.