One sentence, broadly read
Minn. Stat. 347.22 provides that if a dog, without provocation, attacks or injures any person who is acting peaceably in any place where the person may lawfully be, the owner is liable in damages to the full amount of the injury sustained. It says "owner" includes any person harboring or keeping a dog, but the owner is primarily liable.
Summaries of Minnesota case law note that neither common-law defenses nor statutory comparative fault apply; the owner's defenses are provocation and the victim's failure to act peaceably in a lawful place. The Minnesota Supreme Court has treated provocation as voluntary conduct that exposes the plaintiff to a risk of harm from the dog, with knowledge of the risk.