If the director finds that any animal under a hold order pursuant to this chapter cannot, after treatment or care, be safely used for human food purposes, or contains in its body any such deleterious substance in excess of a tolerance established by the director, the director may after notice to the owner or person in possession of the animal, require that the animal be marked or branded or otherwise disposed of in such a manner as to preclude its use for human food. If the animal is fit for use as pet food the director may permit the animal to be so used.