Mo. Rev. Stat. § 209.152

Not to exceed the provisions of the Americans With Disabilities Act, any trainer, from a recognized training center, of a guide dog, hearing assistance dog or service dog, or any member of a service dog team, as defined in section 209.200, shall have the right to be accompanied by such dog in or upon any of the premises listed in section 209.150 while engaged in the training of the dog without being required to pay an extra charge for such dog. Such trainer or service dog team member shall be liable for any damage done to the premise of facilities by such dog.