by ANDREW M. STREIBER, DVM

Q:  My cat is missing and is micro-chipped.  How does that work?  Is it a tracking device or do they scan the cat once found to identify the owner?

A:  Despite the various microchips available today, they all work on the same basic principle – (passive) RFID (Radio Frequency Identification). In other words, a microchip does not act like a tracking device, or as a GPS device would. Instead, your cat would have to be found, taken to an animal shelter or veterinarian hospital and scanned using a specific type of scanner. If all of your registration information is current and correct, you should be contacted by the individual or group who scanned her for the presence of a microchip. However, if your contact information is not current, or the microchip was never registered, the registration information associated with the chip’s unique serial number defaults to the veterinarian to whom that chip was originally sold, and who would have implanted the microchip in your cat.