Abstract: A method and apparatus for the manufacture of a pet food having a transverse, fibrous striated matrix which imparts a superior mechanical cleaning action to the teeth of a pet when chewed. The apparatus includes an extruder through which a fiber bearing food mixture is advanced, the discharge outlet end of which is equipped with a die assembly which induces a state of laminar flow in the food material stream. The die assembly is constructed of a first spacer plate having an annular opening positioned to receive and stabilize the food stream advanced through the die assembly. A breaker plate adjacent to the first spacer plate, receives the flow stabilized food stream and effects a first, discontinuous, alignment of the fibers in the stream. A second spacer plate receives the food stream discharged form the breaker plate. The second spacer plate has a length at least twice that of the first spacer plate, whereby the fibers in the food stream are aligned into a continuous transversely aligned state.