Despite your best efforts, accidents can happen. Someone leaves a door ajar, an intrepid pooch digs under a fence, and your best intentions go awry: Your pet escapes and gets lost. If they’re wearing a collar and identification tag, chances are good that you’ll get them back.

But what if the collar comes off?

To protect their pets, many owners turn to technology, in the form of identification microchips implanted in their pets. Microchips are tiny transponders, about the size of a grain of rice, that can be implanted in your pet’s skin by many veterinarians and animal shelters; some shelters implant one in all pets they place.

Microchips are a good back-up option for pet identification, but should never be the main one. Reading a microchip takes a special scanner, one that an animal control officer or shelter will have, but your neighbor down the street will not. And if Fido wanders off, it’s likely to be a private citizen who encounters them first. That’s why, in the event of accidental separation, identification tags are your pet’s first ticket home.

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That said, microchips provide an extra level of protection in case your pet loses their collar and tags. Providing your pets with both tags and a microchip can help ensure a happy reunion if the unthinkable happens.

How and where are microchips placed?

Microchips are implanted just under the skin, usually right between the shoulder blades. This is done with a large-bore needle and doesn’t require anesthesia.

Each microchip contains a registration number and the phone number of the registry for the particular brand of chip. A handheld scanner reads the radio frequency of the chip and displays this information. An animal shelter or vet clinic that finds your pet can contact the registry to get your name and phone number.

Can a microchip get lost inside my pet?

Your pet’s subcutaneous tissue usually bonds to the chip within 24 hours, preventing it from moving. There’s a small chance that the chip could migrate to another part of the body, but it can’t actually get lost.

How long do microchips last?

Microchips are designed to work for 25 years.

Where can I get my pet microchipped?

Many veterinarians and some animal shelters implant microchips for a small fee. But—and this is very important—just getting a microchip isn’t enough—you also need to register your pet with the microchip company.