St. Louis County, MO Animal Ordinances: Microchipping (2026)

St. Louis County's animal ordinance doesn't require every pet owner to microchip a dog or cat; the chip duty is built into what happens once an animal reaches the County Shelter. 2 requires the Shelter to scan every impounded dog, cat, puppy, or kitten for an electronic identification chip as soon as it arrives, regardless of why it was picked up: at large, surrendered, bitten someone, or otherwise brought in under the chapter's impoundment grounds. If a chip is detected, the Shelter's first move is to contact whoever is listed as the registered owner.

If that registration is stale or the chip was never registered, the Shelter goes up the supply chain instead, contacting the chip manufacturer or registry company for the original purchaser's information and then reaching out to that purchaser directly. ), does the Shelter treat the animal as an untraceable stray eligible for transfer to a rescue, adoption, or humane euthanasia under the chapter's procedures. The chip-scanning duty runs alongside the Shelter's broader duty to make reasonable attempts to identify and notify whoever is responsible for an impounded animal before the hold period runs out.

There's no standalone fine written specifically for a missed or unregistered chip; the chip is simply the tool the Shelter uses to try to get an animal home before the five-day hold expires and animal control moves to transfer, adoption, or euthanasia.