A dog chip, more commonly known as a microchip or pet microchip, is a tiny electronic device that is implanted under the skin of a dog (or other pet) for the purpose of identification. The microchip is about the size of a grain of rice and contains a unique identification number that can be read by a specialized scanner.

The microchip does not have a battery or transmit a signal on its own; instead, it must be scanned by a vet, animal shelter worker, or other authorized individual using a handheld scanner. When scanned, the microchip emits a radio frequency signal that is decoded by the scanner, revealing the unique identification number. This number can then be used to access a database that contains the owner's contact information and other relevant details about the pet.

Microchipping is a safe and painless procedure that can be performed by a veterinarian during a routine check-up or vaccination appointment. The process typically involves using a sterile needle to insert the microchip beneath the skin, usually between the shoulder blades.

The primary purpose of microchipping is to reunite lost or stolen pets with their owners. If a pet is found without identification tags or other means of identifying its owner, a shelter or veterinarian can scan the animal for a microchip and use the information provided to contact the owner. Microchipping is considered a more reliable form of identification than traditional collar tags, as collars can fall off or be removed, whereas a microchip remains with the pet for life.

In many countries, microchipping is mandatory for certain pets, such as dogs, and is widely recommended by veterinarians and animal welfare organizations as a means of ensuring pets can be safely returned to their owners if they become lost or stolen.