Mo. Rev. Stat. § 273.060

The tax on each male dog and each spayed female dog, of which the certificate of a veterinarian or the affidavit of the owner is produced, in this state shall be one dollar per year, and the tax on all other dogs in this state shall be three dollars per year, payable to the county clerk of the county in which the owner resides; provided, that any person or persons operating a licensed kennel of more than ten dogs in which all dogs kept by him or them are confined and not allowed to roam, shall pay a tax of ten dollars, which amount shall be the full amount of tax on all dogs kept by said person or persons as described above.