Microchipping a dog is a great leap forward from a simple collar and tag. But it can be a false sense of security unless you check the chip regularly and keep the registration up-to-date.

Fido was microchipped 10 years ago when Los Angeles Animal Control picked him up off the street as a stray. On a recent trip to the vet to pick up a refilled prescription, I decided to see if it was still in place.

I expected to get a reading as fast as a checker at the grocery store can scan a bar code. As the vet tech moved the handheld scanner over his shoulder blades, no code showed up. Nothing over the left shoulder either. Finally, as she waved the scanner down his right shoulder toward his leg, the numbers showed up.

Had Fido been in an animal shelter, it’s easy to see how a quick swipe from a busy intake worker on a frightened struggling dog could have totally missed it.

Here are five things you should know about microchipping a dog:

1. Microchipping isn’t perfect, but it’s one of the best ways to get a lost dog back.In a study reported by the Journal of the American Veterinary Medical Association in 2009, more than half (52.2 percent) of dogs with microchips were returned to their owners compared to less than 22 percent of the dogs without microchips. (There were 7,700 stray animals in the study.)
2. You have to keep your registration information up to date. A microchip is a tiny electronic chip inside a glass cylinder about the size of a grain of rice. When the scanner passes over it, radiowaves activate the chip and a code is displayed on the scanner screen. That code is registered with the microchip manufacturer.  If you have not registered your dog’s microchip number with your current address, there will be no way to trace the dog back to you. Many people get a microchipped dog from a rescue organization or animal shelter  — or they move — and neglect to change to change the registration information. Most chip companies have websites that give you everything you need to update registration information. There may be a small charge.  In the study cited above, the primary reason more microchipped dogs weren’t returned to their owners was either no registration at all or inaccurate or old information.
3. Check the chip. Ask for this when you go to the vet for annual shots or examinations. Although usually injected between a dog’s shoulder blades, microchips can move with time. While Fido’s microchip didn’t go far, it’s just enough outside the expected area to be missed. There have been cases of the chips failing, although it’s rare. Knowing what the status of your dog’s microchip is gives you the power to take steps if there’s a problem.
4. Give your dog identification tags, even if he or she is microchipped. Nothing is fail-safe, so having a back-up is wise. A collar and identification tag with a phone number may mean that your dog gets home to you faster.  Instead of having to go to a vet or a shelter to have the chip scanned, the person who finds the dog can call you directly. A dog should always have a collar with its rabies tag to show it has been vaccinated.  Relying on a dog license or rabies tag number to be notified if your lost dog is found may take time, especially if city or county offices are closed for weekends or holidays.
5. No matter how careful you are, your dog can get lost. No dog lover believes she could lose her dog. It can happen as fast as the passing of a scampering squirrel, a wafting odor, a cat or another dog. A minute’s distraction and your dog has disappeared. Every step you take — microchipping, checking the chip, identification tags — lowers the risk of losing your best friend forever.

Knowing that Fido’s microchip might be missed with a scanner, I have some decisions to make.

I could have a new microchip injected. It doesn’t require anesthesia or surgery. It is injected with a needle slightly larger than is used with typical shots and vaccinations. But Fido is 12 years old and has a heart murmur. I try to avoid stresses. He’s an indoor dog who doesn’t like dog parks and is almost never off-leash outdoors.

I could make a new identification tag that gives the manufacturer of his chip and the code number.  Having both is important because there is no universal coding system or database.  Each company maintains its own data base. The draw back to a tag is it can be lost. (His AKC Canine Good Citizen tag fell off his collar.)

A last possibility would be to get a custom-made collar with the chip code and maker printed, woven or stitched on to the collar.

While I ponder the options, what would you do in this situation?