Pet microchips, about the size of a large grain of rice, are implanted under the skin of your pet (usually at the back of the neck between the shoulder blades). Each microchip stores your contact information and has a unique serial number. The serial number is registered with an animal microchip database. If your pet wanders off and ends up in a shelter, the shelter will scan your pet’s microchip to pull up his contact information.
Microchips are tiny database of information. They are not geo-locators. In other words, if your pet wanders off, you cannot track his location. Rather, you must wait until someone finds your pet, scans his microchip, and contacts you. Pet microchips are generally considered a very safe and effective technology.
There have been less than a handful of reported instances where pets developed soft tissue tumors (sarcoma and fibrosarcoma) at the sight of the implant. Considering millions of pets are microchipped worldwide, this risk is not even one in a million. Both veterinarians and animals shelters usually perform microchip services, for a fee. Occasionally animals shelters will offer services at a discount to encourage people to microchip their pets.