The Pet Microchip Controversy

One of the worst fears a pet owner can have a beloved pet get lost. Accidents can happen even to the most careful pet owners. A dog or cat could slip out when you open the door, or a meter reader could forget to latch the backyard gate properly.

All your pets should have collars with tags on them, but collars can come off or be removed and tags have the annoying habit of falling off. Pet microchips are a form of permanent identification that can help you get your pet back and cannot be easily removed. But do you have the right pet microchip? In the past, pets have been tragically euthanized because of non-standard chips that shelters could not read.

How Pet Microchips Work

Your veterinarian must inject a microchip that is about the size of a grain of rice into your pet just beneath the skin between the shoulder blades and stays there permanently. The procedure hurts a little more than a vaccination. When you pass a scanner over the microchip, it acts like a transponder and emits a signal. The scanner reads this signal, which is in number form. The shelter or person checking for the microchip must then contact the chip's registry and get the information associated with the microchip. The chip's registry contacts the pet owner and the pet and owner are reunited. Happy ending - or is it?

Pitfalls

In theory, microchips would ensure that no one ever loses a pet again. In reality, well, reality isn't that straightforward. The way the chips are designed is that the owner must register the chip with a registry and keep the information up-to-date. That means that every time the pet owner moves or changes phone numbers, he or she has to contact the registry to change the information.

People can be pretty lax when it comes to changing the tags on their pet's collars. I've worked with both rescue and for veterinarians and it's not uncommon for a dog to show up without tags or with rabies tags from two years ago with the name of an out of state veterinarian printed on it. Or tags with addresses from across the country. If people ignore the tags right in front of them, a microchip is likely to be forgotten - assuming the owner even sent in the registration.

What's more, there's no visual cue that the pet has a microchip. Some people might try to look for the animal's owner instead of taking it to a shelter or a veterinarian's office, thus missing the microchip.

The other problem with microchips is much more alarming, because even if you do everything right you might lose your pet.

Frequency

The problem with microchips is that there is no set standard in the United States. Europe has adopted the ISO (International Standards Organization) standard for the microchip frequency as 135 (134.2) mHz. That means that for one to read an ISO standard pet microchip, one has to have a microchip scanner that operates at 135 mHz. The problem is that because the US doesn't follow the ISO standards, most chips in the US operate at 125 mHz and some even operate at 128 mHz.

Shelters and veterinarians rely on scanners from chip manufacturers. If the scanner doesn't read all frequencies, then there's a possibility that an oddball chip won't get read.

It's Happened Before

According to an article by the JAVMA, the Journal for the American Veterinary Medical Association, in July 2004, one pet owner lost her dog due to a frequency/scanner mix-up. A veterinary hospital had implanted an ISO standard pet microchip with a 135 mHz frequency. When the dog was lost and found by a shelter, the dog was euthanized after a 10 day waiting period because the shelter didn't find the microchip, even though they had a 135 mHz scanner in a box on the shelf. Tragically, the pet owner had called the shelter 30 minutes after her dog had been put down.

Universal Scanners

The good news is after a few of these incidents, manufacturers of pet microchips have handed out universal scanners to check for various frequencies. However, some shelters and veterinary clinics may not have universal scanners and, unfortunately, the reliability of locating a chip isn't 100% even with the correct scanners. A study in 2009 showed a wide range of reliability when it came to scanning. Much depended on the technique of the person doing the scanning, whether there are other electronics present (computers) that can interfere with the scan, and the pet's weight. One of the recommendations of the study was that the animal should be scanned many times with a highly sensitive universal scanner to assure the chip isn't missed.

Recommendations

Having a microchip implanted in your pet is a positive way of identifying him, provided that you understand the limitations. If your dog is lost or stolen, it may be the only way you may get your dog back. If you live outside the US or plan on living outside the US, plan on getting a chip that is ISO compliant and can be read by European scanners. If you live inside the US, ask your veterinarian what chip he or she would recommend and what frequency the chip activates at. In 2007, close to 98% of microchipped pets in the US had 125 mHz frequencies, making it nearly a de facto standard. If your veterinarian wishes to use a different frequency chip, find out his or her reasons. Your veterinarian should be able to guide you to making the right choice, so your pet can be found and you can be reunited.

Microchips are very useful, and it is my belief that everyone should have their pets microchipped, despite the limitations. Knowing these limitations can help you do what you can to ensure you give your pet the best chance at coming home.

References

AVMA:Pet's Death Rekindles Electronic ID Debate

American Humane Association: Microchip Study

Petfinder.org: Pet Microchips

AVMA: Backgrounder: Microchipping for Animals