Once your pet is microchipped, there are only three things you need to do: 1) make sure the microchip is registered; 2) ask your veterinarian to scan your pet’s microchip at least once per year to make sure the microchip is still functioning and can be detected; and 3) keep your registration information up-to-date.

If you’ve moved, or if any of your information (especially your phone number) has changed, make sure you update your microchip registration in the manufacturer’s database as soon as possible.

To remind pet owners to check and update their information, AAHA and the AVMA have established August 15 as “Check the Chip Day.” Take a few minutes to check your information and update it if necessary, and you can rest easy that you’ve improved your chances of getting your pet back if it’s lost or stolen.

The benefits of microchipping animals definitely outweigh the risks. Although we can’t guarantee that a shelter or veterinary clinic will always be able to read every microchip, the risk that this will happen is very low, and getting even lower. Animal shelters and veterinary clinics are very aware of the concerns about missing an implanted microchip, and take extra measures to determine if a microchip is present before a decision is made to euthanize or adopt out the animal. Universal scanners are becoming more available, and solve the challenge of detecting different microchip frequencies.

We do not recommend that you have your pet’s microchip removed, for two reasons. First, based on our review of the studies, the risk that your animal will develop cancer due to its microchip is very, very low, and is far outweighed by the improved likelihood that you will get your animal back if it becomes lost. Second, although implanting a microchip is a very simple and quick procedure, removing one is more involved and may require general anesthesia and surgery.

There have been reports that mice and rats developed cancer associated with implanted microchips. However, the majority of these mice and rats were being used for cancer studies when the tumors were found, and the rat and mice strains used in the studies are known to be more likely to develop cancer. Tumors associated with microchips in two dogs and two cats have been reported, but in at least one dog and one cat the tumor could not be directly linked to the microchip itself (and may have been caused by something else). For more details on the studies, read the AVMA’s literature review on Microchipping of Animals.

The British Small Animal Veterinary Association (BSAVA) maintains a database of adverse reactions to microchips. Since the database was started in 1996, over 4 million animals have been microchipped and only 391 adverse reactions have been reported. Of these reactions, migration of the microchip from its original implantation site is the most common problem reported. Other problems, such as failure of the microchip, hair loss, infection, swelling, and tumor formation, were reported in much lower numbers. For a chart summarizing the BSAVA reports, read the AVMA’s literature review on Microchipping of Animals.

At this time, there is not a central database in the U.S. for registering microchips; each manufacturer maintains its own database (or has it managed by someone else). Because the ISO standards for identification codes have not been adopted in the U.S., the microchips must be registered with their individual registries.

Fortunately, microchip scanners display the name of the microchip’s manufacturer when the microchip is read. Therefore, the likelihood that an animal cannot be identified from its microchip number is very low—that is, unless your pet’s microchip has not been registered or the information is not accurate.

In 2009, the American Animal Hospital Association launched their Universal Pet Microchip Lookup Tool (www.petmicrochiplookup.org), which provides a listing of the manufacturer with which the microchip’s code is associated as well as if the chip information is found in participating registries. The database does not provide owner information for the microchip – the user must contact the manufacturer/database associated with that microchip.

A number of free microchip databases have been launched over the past few years, but many of these databases are not tied directly to the manufacturers’ databases. Fortunately, some of these databases are integrated into the AAHA Universal Pet Microchip Lookup Tool. Any database with which you register your pet’s microchip needs to be regularly updated, and the critical database to keep up-to-date is the one maintained by the microchip manufacturer.

There is no federal or state regulation of microchip standards in the U.S., and different manufacturers are able to produce and patent different microchip technologies with different frequencies. Because of market competition, animal shelters and veterinary clinics are able to choose from several microchip manufacturers and scanners. Microchip scanners are relatively expensive, and it is often cost prohibitive keep one or more of each type of microchip scanner.

This problem can be solved by the use of universal microchip scanners, which are readily available. The use of ISO standard microchips would be a good step in developing a consistent microchipping system in the U.S.

As with almost anything, it’s not a foolproof system. Although it’s very rare, microchips can fail and become unable to be detected by a scanner. Problems with the scanners are also not common, but can occur. Human error, such as improper scanning technique or incomplete scanning of an animal, can also lead to failure to detect a microchip.

Some of the animal-related factors that can make it difficult to detect a microchip include the following: animals that won’t stay still or struggle too much while being scanned; the presence of long, matted hair at or near the microchip implantation site; excessive fat deposits in the region of implantation; and a metal collar (or a collar with a lot of metal on it). All of these can interfere with the scanning and detection of the microchip.

See our literature review for guidelines on scanning procedures to reduce the chances of missing a microchip.

There really is no maintenance required for microchips themselves, although you do need to register the microchip and keep your contact information up-to-date in the microchip registration database. If you notice any abnormalities at the site where the microchip was implanted, such as drainage (oozing) or swelling, contact your veterinarian. Ideally, the microchip should be scanned during your animal’s regular wellness/preventive care exams to make sure that it’s still in place and working as it should.

The best reason to have your animals microchipped is the improved chance that you’ll get your animal back if it becomes lost or stolen.

Absolutely not. Microchips are great for permanent identification that is tamper-proof, but nothing replaces a collar with up-to-date identification tags. If a pet is wearing a collar with tags when it’s lost, it’s often a very quick process to read the tag and contact the owner; however, the information on the tags needs to be accurate and up-to-date. But if a pet is not wearing a collar and tags, or if the collar is lost or removed, then the presence of a microchip might be the only way the pet’s owner can be found.

Your pet’s rabies tag should always be on its collar, so people can quickly see that your pet has been vaccinated for this deadly disease. Rabies tag numbers also allow tracing of animals and identification of a lost animal’s owner, but it can be hard to have a rabies number traced after veterinary clinics or county offices are closed for the day. The microchip databases are online or telephone-accessed databases, and are available 24/7/365.

Definitely! A study of more than 7,700 stray animals at animal shelters showed that dogs without microchips were returned to their owners 21.9% of the time, whereas microchipped dogs were returned to their owners 52.2% of the time. Cats without microchips were reunited with their owners only 1.8% of the time, whereas microchipped cats went back home 38.5% of the time. (Lord et al, JAVMA, July 15, 2009) For microchipped animals that weren’t returned to their owners, most of the time it was due to incorrect owner information (or no owner information) in the microchip registry database – so don’t forget to register and keep your information updated.

When an animal is found and taken to a shelter or veterinary clinic, one of the first things they do is scan the animal for a microchip. If they find a microchip, and if the microchip registry has accurate information, they can quickly find the animal’s owner.

The frequency of a microchip actually refers to the frequency of the radiowave given off by the scanner that activates and reads the microchip. Examples of microchip frequencies used in the U.S. include 125 kiloHertz (kHz), 128 kHz, and 134.2 kHz.

The microchips presently used in pets only contain identification numbers. No, the microchip is not a GPS device and cannot track your animal if it gets lost. Although the present technology microchip itself does not contain your pet’s medical information, some microchip registration databases will allow you to store that information in the database for quick reference.

Some microchips used in research laboratories and for microchipping some livestock and horses also transmit information about the animal’s body temperature.

It is injected under the skin using a hypodermic needle. It is no more painful than a typical injection, although the needle is slightly larger than those used for injection. No surgery or anesthesia is required—a microchip can be implanted during a routine veterinary office visit. If your pet is already under anesthesia for a procedure, such as neutering or spaying, the microchip can often be implanted while they’re still under anesthesia.

A microchip is a small, electronic chip enclosed in a glass cylinder that is about the same size as a grain of rice. The microchip itself does not have a battery—it is activated by a scanner that is passed over the area, and the radiowaves put out by the scanner activate the chip. The chip transmits the identification number to the scanner, which displays the number on the screen. The microchip itself is also called a transponder.