DuPage County, IL Animal Ordinances: Dog Leash Laws (2026)

The leash rule is built from two definitions and one prohibition. Sec. 5-2 defines "Leash" as "a cord, chain, strap or lead not exceeding more than eight (8) feet in length with which an animal may be controlled by the owner or person deemed responsible for the animal while off the owner's premises," and defines "Control" as an animal "secured by a leash, or within the premises of its owner or another person with the consent of the person and prevented from leaving said premises by some suitable barrier or restriction, or confined within a crate or cage, or confined within a vehicle." A "stray animal" is then defined, in the same section, as simply "any owned animal that is not controlled." Sec. 5-3(O)(1) makes the operative rule explicit: "No person shall permit at any time his animal to: 1. Run uncontrolled." Read together, any dog off its owner's property in unincorporated DuPage County that is not on a leash of eight feet or less, or otherwise confined, is out of compliance.

A stricter, separate leash duty applies once a dog has been found dangerous. Sec. 5-13(B) lets the administrator, the state's attorney, or any County resident sue in Circuit Court to enjoin a dangerous-dog owner from letting the animal leave the premises "when not under the control of a leash of other recognized methods of physical restraint." Sec. 5-11 and 5-12 separately incorporate the Illinois Animal Control Act's dangerous-dog and vicious-dog provisions (510 ILCS 5/15.1-15.3, 5/15, 5/26) wholesale into county law.