Microchips reunite pets with families

Short haired cat being checked for a microchip
In this article
  • Understand the benefits of microchipping.
  • Learn how microchips work and the importance of keeping your chip’s registration up to date.
  • Find FAQs on microchipping.

For animals that get separated from their owners, proper identification is a ticket home.

A microchip is a very small device, about the size of a grain of rice, that is placed under an animal's skin using a hypodermic needle—much like giving the animal a shot. The microchip contains a unique identification number that matches up with the owner's contact information maintained in a database. When a scanner is passed over the chip, the scanner displays the number. If the owner's contact information is up to date in the microchip database, the owner can be located quickly.

Benefits of microchipping

Permanent identification of animals can be a challenge. Identification tags are an important and effective means of identification, but only if they are in place on an animal when it becomes lost. For animals that don’t wear collars or easily escape their collars, microchips may be especially valuable.  Microchips provide a reliable, and often less painful, method of permanent, unalterable animal identification.

The AVMA endorses the implantation of electronic identification in companion animals. But microchips aren’t a substitute for proper external identification of animals. Microchipped pets should also wear collars with proper identification. License tags, rabies tags and personal visual identification are all components of a comprehensive pet identification program.

How they work: Animal microchip types and frequencies

Microchips contain four components:  a capacitor, antenna, connecting wire, and a covering.  They are battery-free and sealed in biocompatible glass or polymer covered by a sheath to help prevent them from moving around once implanted.

Microchips are activated by a low-power radiofrequency signal emitted by scanners. Electromagnetic induction generates electricity in the antenna and transmits the information stored in the microchip.  When scanned, the microchip transmits a unique, preprogrammed identification number.  Some microchips also collect and transmit body temperature data.

The use of standard microchip implantation sites makes it easier to detect an implanted microchip. Veterinarians know how and where to implant microchips to optimize their effectiveness.

Microchips are produced by various manufacturers, and there is no agreed-upon “American standard” for microchip frequencies.  The AVMA, American Animal Hospital Association, World Small Animal Veterinary Association, American Kennel Club, American Society for the Prevention of Cruelty to Animals, and many other organizations, endorse the use of electronic identification in animals and support the implementation of International Standards Organization (ISO) standards for microchips in the United States.

The American National Standards Institute also supports the ISO standards for microchips. But both ISO-compliant and non-ISO-compliant microchips are used in the United States.  The ISO standard includes assignment of a 15-digit numeric identification code to each microchip.  Non-ISO (125- or 128-kHz) microchips contain nine or 10 digits.

Microchip registration: Keep it up to date!

Reuniting lost animals with their owners relies on accurate contact information being connected with the microchip. The microchip itself contains only a registration number. Animal owners must register their pets’ microchips and keep their contact information current in the registration database. Without accurate contact information in the database, a lost animal might not be returned to its owner even after its microchip is scanned.

August 15 has been designated as Check the Chip Day each year, when all owners are encouraged to confirm and update the contact information registered with their pets’ microchips. The American Animal Hospital Association’s universal pet microchip lookup tool allows users to enter a microchip code, then directs them to participating microchip registries associated with that microchip and its manufacturer.

Microchipped animals should be scanned during their regular preventive care exams to confirm that their microchip is still functioning properly.