Mont. Code Ann. § 81-2-108

It shall be unlawful for any owner, agent, or person in charge of any domestic animal or animals that are known to be suffering from or exposed to a dangerous, infectious, contagious, or communicable disease to permit such animal or animals to run at large on the public range or public highway. It shall be the duty of the owner or agent or person in charge of animals which died or they have reason to suspect did die from an infectious, contagious, communicable, or dangerous disease to properly bury or burn the same.