As with some jurisdictions, Maryland law holds the owners of dogs that attack and injure others while running at large strictly responsible for those injuries. The animal’s owner is responsible for any injury or death caused by the dog while running at large, unless the victim is committing a crime, trespassing on the owner’s property, or tormenting the animal. The fact that injury occurs created a presumption that the owner knew the dog had vicious tendencies. A defense is available to the owner if they can prove that they did not know if the dou’g viscous qualities. For a dog that is not running at large, an owner will still be held liable for an attack resulting in injury. Prior to the enactment of the strict liability provisions, Maryland did, and still does, recognize the liability of the owner based on negligence principles. To recover against the owner of a dog based on a negligence claim, the victim must show that the owner knew, or should have known, that the dog was vicious.
Perhaps the classic way to prove that level of knowledge was that the dog had attacked before- the so called “one bite” rule- but showing a prior attack is not required.
Other circumstantial evidence demonstrating that the owner had reason to know the dog would attack may be sufficient for a finding of negligence.