Found a lost pet? How the microchip gets them home

Updated June 12, 2026

Take the pet to any veterinary clinic or animal shelter. They have universal chip scanners, they’ll usually scan a found pet free of charge, and scanning is one of the first things staff do. The scan shows a number, not an address. That number is then looked up to find which registry can reach the owner.

Is the pet safe to approach?

Move slowly, crouch rather than loom, and let the animal come to you; food helps more than pursuit. If the animal is injured, trapped, or behaving aggressively, don’t handle it. Call your local animal control and describe where it is. If you’re bitten or scratched, contact a doctor or your local health department.

Where can I get a found pet scanned?

Any veterinary clinic or animal shelter, and many rescue organizations. Even some police and fire stations keep universal scanners. Scanning a found pet is a standard service and usually free; you generally don’t need an appointment for a quick scan.

One practical tip: scanners are good but not perfect. In a JAVMA field study across 3,949 shelter animals, no scanner detected 100% of chips: universal scanners read at least 94.8% of the two standard higher-frequency chip types, and one did markedly worse on an older low-frequency type. If the first pass finds nothing, ask for a slow second pass over the whole body. Chips can sit off-center.

How does the microchip work?

A microchip is not a GPS tracker. It has no battery and stores exactly one thing: a number. The scanner’s signal powers the chip just long enough to read that number.

From there: the number goes into the AAHA Universal Pet Microchip Lookup, a free public tool that shows which registries hold a registration for that chip. If none do, it shows which company manufactured it. The lookup never displays the owner’s name or contact details; the registry holding the registration makes the contact, or shares information according to its own process. Privacy lives at the registry, which is why the system works at all.

What if there’s no chip, or the registration is dead?

It happens more than you’d expect: in a study of 7,704 microchipped animals entering shelters, owners were successfully found for about 74% of stray dogs and 64% of stray cats. The registration, not the chip, was usually the weak link. If the lookup shows no registry, it will still show the chip’s manufacturer, and shelter staff know the follow-up routes from there.

Either way: file a found report with your local shelter and animal control (that’s where owners look first) and post on your local lost-and-found channels. If you’re wondering whether you can keep the pet, the honest answer is that stray-hold rules vary by state and city; your local shelter knows the rules where you live.

If you’re reading this as an owner

The other half of this story is keeping your own pet findable. Registrations go stale quietly: moves and changed phone numbers are the most common reason a scanned chip doesn’t get a pet home. Here’s how to check your pet’s registration in about ten minutes.

Common questions

Do pet microchips have GPS?

No. A microchip is a passive chip with no battery that stores only a registration number. It can’t be tracked; it can only be read by a scanner held over it.

Is it free to have a found pet scanned?

Usually, yes. Veterinary clinics and shelters scan found pets free as standard practice. Calling ahead is polite but rarely necessary.

Can I look up a chip number myself?

Yes. The AAHA Universal Pet Microchip Lookup is free and public. It shows which registry holds the registration, not the owner’s information.

What if no owner is found?

File the found report with your local shelter and animal control anyway, and keep the report active. Stray-hold and adoption rules vary by jurisdiction; the shelter can tell you what applies where you live.

What if the chip was never registered?

The lookup will show the chip’s manufacturer instead of a registry. File the found report regardless (shelters have reunification routes beyond the chip), and if you end up adopting, register the chip in your own name.