We use AVID FriendChips.  The microchip is inserted under the skin using a needle and syringe.   The procedure is very quick and can be performed on an outpatient basis, during an exam, or during a surgery.   Local anesthesia is available for pets (or their owners) that may be extra sensitive.  Registration is available via AVID (PetTrac),  through Home Again, or through the AKC (recommended).     If  your pet is lost, the animal shelter (or humane society or vet) can scan your pet,  find you and reunite you with your pet.  It is a little extra safety net to make sure that you can find your pet again if they are lost.   

About AVID:

 The microchip is a tiny computer chip which has an identification number programmed into it and is encapsulated within a biocompatible material. The whole device is small enough to fit inside a hypodermic needle and can be simply injected under the skin of our pets, where it will stay for the life of the animal. This provides a permanent, positive identification which cannot be lost, altered or intentionally removed - a safe, simple and inexpensive way to protect your pet against loss or theft.

The computer memory in the AVID Microchip contains a unique number - no two animals will ever have the same number. A radio signal is used to read this number through the skin of your pet. In addition to the number, the microchip generates a reliability check to guarantee that your pet's identifying number is read accurately. This all takes place in less than 40 milliseconds.