Jefferson County, MO Animal Ordinances: Breed Restrictions (2026)

290 lets the Animal Control Manager declare any animal, of any breed, 'potentially dangerous' or 'dangerous' once it bites, attacks or injures a person or another domesticated animal, or shows high aggression witnessed by an Animal Control Officer. The Manager lists potentially dangerous animals on a Potentially Dangerous Animal Registry and dangerous animals on a separate Dangerous Animal Registry, and each written declaration spells out the conditions the owner must meet to keep the animal. To keep a dog or other animal declared dangerous, the owner must show the Animal Control Manager that it is kenneled inside the home or in a proper enclosure posted with a warning sign at every entrance, that it is covered by at least $100,000 of liability insurance naming the animal, with the insurer required to give the county ten days' notice before canceling the policy, and that the animal carries a current county license, rabies vaccination, spay/neuter and microchip.

Outside the enclosure, a dangerous animal must be muzzled and held on a chain or leash of four feet or less by a person capable of controlling it, and it cannot be tethered to a tree, post or building. Owners who lose insurance coverage, let the enclosure lapse, or let the animal outside unmuzzled face immediate confiscation by an Animal Control Officer, and the county forfeits and can destroy the animal outright if it attacks another animal or seriously injures or kills a person. A declaration can be appealed under Chapter 536, RSMo, but the appeal does not pause compliance with the declaration's conditions.