O'Fallon, MO Animal Ordinances: Microchipping (2026)

O'Fallon Code Section 210.180(A) provides that any dog, cat, or ferret which is apprehended running at large or which has bitten a human being or animal shall be permanently identified by the implantation of an encoded, inert chip or like device that contains a unique identifier capable of providing a permanent record of the animal's identity. The section specifies that the device must be implanted prior to the release of the animal from impoundment, meaning it is a condition of getting the pet back rather than a standing citywide mandate for every pet owner.

Section 210.180(B) places the cost of the permanent identification on the owner as a fee, on top of the separate impoundment redemption fees set in Section 210.110, which run $20 for a first impoundment, $40 for a second, and $60 for a third or subsequent impoundment, plus daily boarding costs charged by the animal shelter. This targeted chipping requirement works alongside the at-large ban in Section 210.030(A)(1) and the county rabies-tag requirement in Section 210.030(A)(5): an animal that has never been picked up running loose or involved in a bite incident is not required by this chapter to carry a microchip, but repeat at-large offenders and biting animals are permanently traceable once processed through the City's animal shelter under Section 210.080.