A statute since 2009
RSMo 273.036 makes the owner or possessor of a dog that bites, without provocation, a person on public property or lawfully on private property strictly liable, regardless of the dog's former viciousness or the owner's knowledge. It took effect in 2009 and ended the one-bite rule.
If the victim had fault, the damages are reduced by the same percentage. A liable owner also pays a fine of up to $1,000, and the remedies are in addition to other statutory or common-law remedies. The statute applies to bites, not other injuries, so a knockdown claim runs through negligence.