I just completed a round trip between the Front Range of Colorado and New York City, and so did a cat named Willow. I have to say, though, that her travels are far more remarkable than mine.

Willow lived in Broomfield, Colorado five years ago, but escaped from her home after contractors left a door open. After an unsuccessful search for her, Willow’s owners assumed that she had become a meal for some of the wildlife that frequents our neck of the woods. Thankfully, they were wrong.

Somehow, Willow made her way from Colorado to New York City, where five years after her disappearance, she was brought into an animal shelter by a gentleman who found her wandering the streets. Shelter personnel scanned her for a microchip, and bingo — up popped her Colorado owners’ contact information.

This is the most dramatic story I’ve heard supporting the recommendation that all pets be microchipped.

Microchips are really quite amazing. They’re about the size of a grain of rice and can be inserted under a pet’s skin using what is essentially a large syringe and needle. Lots of people say that the procedure can be done without the use of an anesthetic, but frankly, that needle is pretty big. I prefer to place microchips when pets are under anesthesia for other reasons (spays, neuters, dental cleanings and the like), or inject a small amount of local anesthetic into the area first.

But, microchips are a complete waste of time and money if owners don’t keep their information current with the company to which they are registered. You might think that the microchip itself contains your name, phone number, and address, but that is not the case. The chip simply lets the scanner know what company needs to be contacted and presents an identification number unique to that chip. A company representative can then look up that ID number, and as long as the information in the database is accurate, pet and pet parent can be reunited.

Props to Willow’s owners for keeping their information current. They had moved to a nearby town during Willow’s absence but stayed in touch with the microchip company.

The microchipping system is not perfect, however.  One problem is that some scanners can only read certain types of chips. The situation is improving with the recent development of "universal" scanners, but microchips can still be missed. For this reason, owners should also outfit their dogs and cats with collars and tags. These low-tech solutions have the added benefit of letting a neighbor or other Good Samaritan who doesn’t have access to a microchip scanner quickly help pets make their way back home.

I’ve had more than one of my own pets benefit from their collars and tags, but I haven’t had to put their microchips to the test yet. How about you?

Dr. Jennifer Coates

Image: Willow, a 6-year-old calico cat / via the Denver Post/Bebeto Matthews for the AP