Mo. Rev. Stat. § 196.695
The term "filled milk" means any milk, cream or skim milk, whether or not condensed, evaporated, concentrated, powdered, dried or desiccated, to which has been added, or which has been blended or compounded with, any fat or oil other than milk fat, so that the resulting product is in imitation or semblance of milk, cream or skim milk, whether or not condensed, evaporated, concentrated, powdered, dried or desiccated, which has been melted or refined by heating, boiling or mixing; provided, that the above definition shall not include any distinctive proprietary food compound, not readily mistaken in tests for milk or cream, or for evaporated, condensed or powdered milk or cream; provided, however, that such compound is prepared and designed for feeding infants and young children and customarily used on the order of a physician; is packed in individual cans containing not more than sixteen and one-half ounces and bearing the label in bold type, that the contents are to be used only for said purposes; is shipped in interstate or foreign commerce exclusively to physicians, wholesale or retail druggists, orphan asylums, child welfare associations, hospitals and similar institutions and generally distributed by them.
§ 196.695, RSMo