Mo. Rev. Stat. § 269.160

Vehicles, when loaded with the body of an animal, shall be driven directly to a substation or to the place of disposal, except that the driver may stop to pick up other dead bodies, but he shall not drive upon the premises of any person unless he first obtains the permission of such person and he shall avoid creating any nuisance during such transportation and in the event any drippings, seepage or spillage from malfunction or accident should escape from such vehicle, to his knowledge, he shall clean up the same and remedy such escape.