DuPage County, IL Animal Ordinances: Microchipping (2026)

Sec. 5-5(B) governs what happens once DuPage County Animal Services learns an animal has bitten a person. The administrator has the owner confine the biting animal under a licensed veterinarian's observation for ten days, starting within twenty-four hours of the bite, and requires that "[a]ll dogs and cats under observation, owned by a resident of DuPage County, shall be implanted with a microchip approved by the administrator at the time of the first examination unless the animal is to be euthanized." The microchip number then has to be reported to DuPage Animal Services on the county's Rabies Observation Notice, tying the chip directly to the bite investigation file.

The same microchip requirement is not limited to biting incidents. Sec. 5-7(A)(2) requires that all reclaimed strays, dogs and cats picked up as impounded animals, be implanted with an administrator-approved microchip before release, even absent a bite. Sec. 5-37(B) repeats the requirement at the point of redemption from the pound, and Sec. 5-34(A) requires a microchip before DuPage County will issue a commercial guard-dog registration certificate. Veterinarians handling a confinement case must also record the chip number on the county's Rabies Observation and Confinement of Biting Animal Form under Sec. 5-32(B), and the microchipping duty runs to the administrator's approved chip standard, not just any implant.