Most states have specific laws governing the possession of dangerous wild animals, and the liability of landowners for injuries caused by wild animals on their property. Ferae naturae is a common law doctrine (created by judges in court opinions) meaning "animals of a wild nature or disposition," and traces its origins back to the Roman empire. Under the doctrine of ferae naturae, wild animals are presumed to be owned by no one specifically, but by the people generally.

In many states the rule of law has developed that a landowner cannot be held liable for the acts of indigenous wild animals occurring on his or her property unless the landowner has actually reduced the wild animals to possession or control, or introduced a non-indigenous animal into the area.

In Oregon, the possession of exotic or wild animals is regulated by state statutes, specifically under Oregon Revised Statutes (ORS) 609.305 to 609.335. These laws require individuals to obtain a permit for possessing, importing, or selling exotic animals. The state defines exotic animals and sets forth the requirements for obtaining a permit, including demonstrating that the person has adequate knowledge and facilities to care for the animal. Regarding liability for injuries caused by wild animals, Oregon follows the common law doctrine of ferae naturae, which means that landowners are generally not liable for injuries caused by wild indigenous animals on their property unless the landowner has taken possession or control of the animal, or has introduced a non-indigenous species that causes harm. This principle is consistent with the traditional rule that wild animals are owned by no one in particular but by the people in general, until an individual takes possession of them.