Second Microchips: Should You Re-Chip Your Pet?

Have you ever been told that your pet’s microchip no longer works, or cannot be picked up by a scanner? Perhaps someone claimed it was an “international microchip” that won’t be read in the United States. Or, maybe your pet’s microchip has migrated from the shoulders to another part of the body. If so, you’ve probably asked yourself a common question: Does my pet need a second microchip?

People often email us asking whether they should re-chip their pets, and we always give the same answer: It depends. A microchip is usually good for the life of the pet. It does not wear out or turn off.  So, in the vast majority of cases, the chip should never need to be replaced. Of course, there is an exception to every rule. We can break this list into three categories: The Good, The Bad, and The Ugly.

Good Reasons to Re-Chip:

The owner is moving out of the country and needs an international chip

As you may recall from our “5 Things You Didn’t Know About Microchips” blog, many countries require a 15-digit, 134.2kHz ISO standard chip. It’s not really accurate to call it an “international chip,” because we have plenty of them in the U.S., too. We just don’t mandate it. Check animal codes in the destination country to see if “ISO 11784” or “ISO 11785” compliant pet microchips are required. Remember, just knowing the chip company is not enough to tell whether your existing chip is compliant. Look to length – if the microchip number is less than 15 digits, the microchip is not ISO standard, so go ahead and re-chip away. Not traveling after all? Your 9 or 10 digit microchip will still work just fine here in the States.

The microchip has migrated, is no longer working or has fallen out

Microchip migration is actually very rare. A major BSAVA microchip study examining 3.7 million pets found that true migration occurs in less than 1 out of 10,000 cases! Microchip failure is even less common. In the vast majority of instances where a chip is “unreadable,” a non-universal scanner is really to blame. It’s worth perusing our microchip scanner cheatsheet and having a talk with your vet to be sure she is scanning for all three chip frequencies before re-chipping.

If your pet’s chip is among the migrated minority, you may need to do some soul-searching and see whether a second microchip makes sense for your pet. If animal professionals don’t scan thoroughly, your pet’s chip may be missed. If your pet ends up with two microchips, you will need to register and update both registrations for the same reason.

Bad Reasons to Re-Chip:

The microchip type is unreadable in the U.S. or is an “international chip”

False! Although the United States has not yet standardized our pet microchips, we have abundant ISO standard microchips here, too. So basically, the microchip world looks like this:

All three frequencies commingle happily in our national microchip melting pot. “But wait,” you may say, “If my vet/shelter/rescue’s scanners aren’t reading all frequencies, how will they find those microchips?” They won’t. If your organization has an outdated non-universal scanner, it will miss chips. That means hardworking American pets with perfectly good registered microchips will not be able to make it home. Do your part to help our country’s cats and canines by educating your community! (Even better, why not hold a pet fundraiser and donate a new universal scanner?)

The microchip company no longer exists, is too expensive or is downright rude

As frustrating as our two-legged brethren in customer service can be, double-chipping won’t make the first chip disappear. Luckily, you aren’t tied to that company. Thanks to the AAHA’s Universal Pet Microchip Lookup Tool, shelters and vets can search any U.S. microchip and see exactly where it is registered.

Even if your microchip is registered with a different company than the one that originally sold it, animal care professionals will be able to find your registration immediately using this free website. Many microchips are cross-registered anyway, so this website is really the only way to know for sure which company has pet owner contact information for a microchip. Therefore, all shelters and vets should use this tool as the first step in getting pets home. Use whichever registry you like. Just make sure your registry participates in the Pet Microchip Lookup Tool*. If not, your pet will be at the mercy of a lucky guess.

(*At time of writing, all common microchip registries participate in petmicrochiplookup.org except for Avid. A current list of AAHA’s participating companies is available on their website).

Tip: If you don’t want to update multiple registrations for the same chip, at least provide the old company with your new registry’s phone number, email, etc. This will allow the old company to point callers toward your current registration. 

Ugly Reason to Re-Chip:

The microchip is registered to someone else and the owner can’t update it

Why is this an ugly reason? First off, the microchip registration is not a good place to air grievances about a pet’s ownership or rightful home. Believe it or not, most municipalities do not consider a microchip legal proof of ownership. If that sounds crazy or if your microchip provider has told you otherwise, think about it this way: Anyone can put a chip in a pet, just like anyone can put an ID tag on a collar. If someone really wanted to microchip and register your pet without your permission, a few seconds of distraction at the dog park or a dexterous hand through your fence would do the trick. Even for your pet’s existing chip, there’s nothing to stop anyone from registering your number with another registry that you don’t check (many pets wear their microchip number printed right on their ID tags – no scanner needed).

For these reasons and several others, if you are experiencing an ownership dispute regarding your pet, you need to work it out legally. Shelters want to see adoption contracts, municipal licenses, ownership release forms and other documents proving you are the pet’s legal owner. Be sure these things are in your hands and not someone else’s. If you have them, updating the microchip registration is easy. Your local animal control can help you speak with the registry.

Maybe you and the previous registrants get along just fine. That’s great, but if they have not yet transferred the microchip registration to you, how will they respond when your pet is found? Do they know when you move or change phone numbers? If it’s no longer their pet, odds are they aren’t updating their info, right?

Again, even one unregistered chip can spell disaster. Incorrectly registered microchips can be worse than no microchip at all. The shelter or vet will see old information, try to contact that owner and assume they’ve done their best to get the pet home. Not only will it hurt your pet’s chances of a happy reunion, it wastes precious time and resources for our shelters. Double bummer! Do the right thing and stick with the chip you’ve got.