Mercer County, NJ Animal Ordinances: Dog Leash Laws (2026)

The Park Commission's 'Pets, Horses' section sets the leash standard for every county park and recreation area: a dog, cat or other furred animal must be in the custody or under the control of its owner and restrained by a leash not exceeding 6 feet in length, and owners cannot let their animal run at large except inside a park's designated dog park areas. The same section makes owners responsible for cleaning up after their animals and disposing of the waste properly, a duty that applies wherever pets are allowed in the park system, not just in off-leash dog parks.

Horses and other larger animals get their own, stricter rule: no person may ride, drive, lead or keep a horse or other animal in a county park except on roads, trails or areas the Commission specifically designates for that use, and no animal may be hitched to any tree or shrub. The rules separately bar using any animal or bird for hunting on Park Commission property, a restriction that applies on top of the leash and control requirements. Because the rule ties leash length to a hard 6-foot cap rather than a general 'under control' standard, an owner using a longer leash, a retractable leash extended past 6 feet, or no leash at all outside a designated dog park is out of compliance even if the animal is well-behaved. Enforcement runs through Park Rangers, at (609) 443-8956, and the Penalties section applies the same court-fine structure used for the rest of the rulebook.