Microchipping FAQ
Reprinted from American Veterinary Medical Association
Q: What is a microchip?
A: 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 radio waves 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.
Q: How is a microchip implanted into an animal? Is it painful? Does it require surgery or anesthesia?
A: 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 undergoing anesthesia for a procedure, such as neutering or spaying, the microchip often can be implanted while they're still under anesthesia.
Q: What kind of information is contained in the microchip? Is there a tracking device in it? Will it store my pet's medical information?
A: The microchips presently used in pets only contain identification numbers. The microchip is not a GPS device and cannot track your animal if it gets lost. Although the 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.
Q: Should I be concerned about my privacy if my pet is microchipped? Will someone be able to track me down?
A: No. You don't need to be concerned about your privacy. The information you provide to the manufacturer's microchip registry will be used to contact you in the event your pet is found and its microchip is scanned. In most cases, you can choose to opt in or opt out of other communications (such as newsletters or advertisements) from the manufacturer. The only information about you ]in the database is the information that you choose to provide when you register the chip or update your information. There are protections in place so that a random person can't just look up an owner's identification.
Remember that having the microchip placed is only the first step, and the microchip must be registered in order to give you the best chances of getting your pet back. If that information is missing or incorrect, your chances of getting your pet back are dramatically reduced.
Q: What does "microchip frequency" mean?
A: The frequency of a microchip refers to the frequency of the radio wave given off by the scanner that activates and reads the chip. Examples of microchip frequencies used in the U.S. include 125 kiloHertz (kHz), 128 kHz, and 134.2 kHz.
Q: I've heard about something called "ISO standard." What does that mean?
A: The International Standards Organization, or ISO, has approved and recommended a global standard for microchips. The global standard is intended to create an identification system that is consistent worldwide. For example, if a dog implanted with an ISO-standard microchip in the U.S. travels to Europe with its owners and becomes lost, the ISO-standard scanners in Europe would be able to read the dog's microchip. If the dog was implanted with a non-ISO microchip and the ISO scanner was not forward- and backward-reading (universal), the dog's microchip might not be detected or read by the scanner.
The ISO standard frequency is 134.2 kHz.
Q: What are universal (forward- and backward-reading) scanners? How do they differ from other scanners?
A: Forward-reading scanners only detect 134.2 kHz (ISO standard) microchips, but will not detect 125 kHz or 128 kHz (non-ISO standard) microchips. Universal scanners, also called forward- and backward-reading scanners, detect all microchip frequencies. The main advantage of universal scanners is the improved chance of detecting and reading a microchip, regardless of the frequency. It also eliminates the need for multiple scanners with multiple frequencies.
Q: How does a microchip help reunite a lost animal with its owner?
A: When an animal is found and taken to a shelter or veterinary clinic, one of the first things the staff does 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.
Q: Will a microchip really make it more likely for me to get my pet back if it is lost?
A: Definitely! In fact, a study of more than 7,700 stray animals at animal shelters in 23 states showed that microchipped animals are far more likely to be returned to their owners. In that study, microchipped stray dogs were returned to their owners at more than double the overall rate for all stray dogs. For stray cats, the difference in return rates was even more dramatic.
For microchipped animals that weren't returned to their owners, the most common reason was an incorrect or disconnected owner telephone number in the microchip registry database. So don't forget to register your pet’s microchip, and keep your contact information up to date.
Q: Does a microchip replace identification tags and rabies tags?
A: 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—if the information on the tag is accurate. 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 accessed by telephone, and are available 24/7/365.
Q: I just adopted a pet from the animal shelter. Is it microchipped? How can I find out?
A: If the shelter scanned the animal, they should be able to tell you if it is microchipped. Some shelters implant microchips into every animal they adopt out, so check with the shelter and find out your new pet's microchip number so you can get it registered in your name.
Most veterinary clinics have microchip scanners, and your veterinarian can scan your new pet for a microchip when you take your pet for its veterinary checkup. Microchips show up on X-rays, so that's another way to look for one.
Q: Why should I have my animals microchipped?
A: 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.
Q: I want to get my animal(s) microchipped. Where do I go?
A: To your veterinarian, of course! Most veterinary clinics keep microchips on hand. So, it's likely that your pet can be implanted with a microchip the same day as your appointment. Sometimes local shelters or businesses will host a microchipping event, too.
Q: Why can't I just buy the microchip and implant it myself?
A: It looks like a simple enough procedure to implant a microchip—similar to giving an injection, right? Well, yes and no. It's very important that the microchip is implanted properly. Using too much force, placing the needle too deeply, or placing it in the wrong location can not only make it difficult to detect or read the microchip in the future, but can also cause life-threatening problems. Microchips should really be implanted under supervision by a veterinarian. That's because veterinarians know where the microchips should be placed, how to place them, and how to recognize the signs of a problem and treat one if it occurs.
Q: Once the microchip has been implanted, do I need to monitor my pet?
A: Follow your veterinarian’s instructions for monitoring your pet after it has been microchipped. In general, if you notice any abnormalities at the site where the microchip was implanted, such as drainage (oozing) or swelling, contact your veterinarian.
Q: What should I do to "maintain" my pet's microchip?
A: Once your pet is microchipped, there are only three things you need to do:
Make sure the microchip is registered.
Ask your veterinarian to scan your pet's microchip at least once a year to make sure the microchip is still functioning and can be detected.
Keep your registration information up-to-date.
If you've moved, or if any of your information (especially your phone number or address) has changed, make sure you update your microchip registration in the manufacturer's database as soon as possible.
August 15 is designated as Check the Chip Day each year, and that’s the perfect time to take a few minutes to check your pet’s microchip registration information and update it if necessary.
Q: I heard about a dog that was euthanized by a shelter because his microchip wasn't detected by the shelter's scanner. How can I know that won't happen to my pet?
A: Unfortunately, there have been instances of this happening in the past, and it’s heartbreaking. The good news is that this is unlikely to happen now because of the availability of universal (forward-and-backward reading) scanners.
Although the presence of a microchip is not a 100% guarantee that you will get your pet back if it's lost or stolen, it does dramatically increase the chances you will be reunited with your pet...as long as you keep the registration information up to date.
Q: Why are microchips sometimes not found?
A: As with almost anything, it's not a foolproof system. Although it's very rare, microchips can fail and become undetectable by a scanner. Problems with the scanners also can occur, though they’re not common. Human error, such as improper scanning technique or incomplete scanning of an animal, can also lead to failure to detect a microchip.
There also are animal-related factors that can make it difficult to detect a microchip, including animals that won't stay still while being scanned; the presence of long, matted hair at or near the microchip site; excessive fat deposits in the area where the chip is implanted; 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.
Q: My pet has two microchips implanted, with different frequencies. Do I need to have one removed?
A: No. You don’t need to have one of the microchips removed, and the two will not interfere with each other. The microchip detected by the scanner will depend on the scanner used—a universal scanner probably will detect both chips if it’s reset after finding the first one. A scanner that reads only one microchip frequency will only detect a microchip of that specific frequency.
If you know your pet has more than one microchip implanted, make sure you keep the database information updated for each microchip. That way, you can be contacted and your pet returned to you no matter which microchip is detected.
Q: My pet has a non-ISO-standard, 125 kHz microchip implanted. Can I have it implanted with an ISO-standard, 134 kHz microchip?
A: Yes. Both chips will function normally.
Q: I'm relocating to a country that requires ISO chips. What do I need to do?
A: If your pet has no microchip or has a non-ISO-standard chip, you’ll need to have an ISO microchip implanted before it will be allowed into that country. You may also have to meet other requirements unrelated to microchipping. Here’s what you need to know about animal travel and transport.
Q: I'm relocating to a country that requires ISO chips, and my pet has an ISO chip. What do I need to do?
A: In general, your pet won't need another microchip to be allowed into that country; however, you should check on the destination country's animal importation regulations as you plan your relocation. That's not the only thing you need to know: countries differ widely on their importation rules, including different regulations about required vaccinations and quarantine periods once the animal enters that country. If you do some research and preparation, your pet's relocation can go smoothly. Contact the country of origin to determine their requirements regarding microchips as well as vaccinations, certificates, etc. Alternatively, you can contact an experienced animal shipper who is well-versed in the processes and regulations affecting animal shipment.
Q: Why isn't it a requirement that all shelters and veterinary clinics use the same microchips and readers? Or, if there are different frequencies of microchips and each requires a separate scanner, why aren't they required to have one of each scanner so microchips are never missed?
A: 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 can choose from several microchip manufacturers and scanners. Microchip scanners are relatively expensive, and it's often cost-prohibitive to 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.
Q: When I have my pet microchipped, is there one central database that registers the information and makes it available to animal shelters and veterinary clinics in case my pet is lost or stolen?
A: There isn’t a central database for registering microchips in the U.S. Each manufacturer keeps its own database. Fortunately, when microchip scanners display a microchip’s number, that can be used to identify the chip's manufacturer. This makes it unlikely that an animal can’t be identified from its microchip number—unless the pet's microchip hasn’t been registered or the owner’s contact information is incomplete or inaccurate.
Also, the American Animal Hospital Association’s universal microchip lookup tool allows someone to enter a pet’s microchip number to find out what manufacturer(s) to contact about that microchip. The tool does not provide owner information for the microchip—the user has to contact the manufacturer/database associated with the chip.
Other free microchip databases are available, but many of these are not tied directly to the manufacturers' databases. Any database with which you register your pet's microchip needs to be updated regularly, and the critical database to keep up-to-date is the one maintained by the microchip manufacturer.
Q: What are some of the problems associated with microchips? How common are they?
A: Adverse reactions to microchips are uncommon, but they do happen. The most common one is migration of the microchip from its original implantation site. Other issues include failure of the microchip, and hair loss, infection, swelling or tumor formation near the implantation site. More serious problems, and even life-threatening ones, can occur if a chip isn't implanted properly, so it's important to have a veterinarian perform or oversee the microchipping.
Q: I've heard lately that microchips cause cancer. Do they?
A: Although there have been reports of mice and rats developing cancer associated with implanted microchips, the majority of these mice and rats were being used for cancer studies when the tumors were found, and the types of rats and mice used in the studies are known to be more likely to develop cancer. There have been only a very small number of cases in which a microchip was associated with a nearby tumor, and no causal effect has been proven.
Q: I don't want my pet to get cancer. Should I have my pet's microchip removed?
A: 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 a 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.
Q: Do the benefits of microchipping outweigh the risks?
A: Yes. The benefits of microchipping animals far outweigh the risks. Although there’s no guarantee that a shelter or veterinary clinic will be able to read every microchip, the risk that a chip won’t be read is very low, and getting even lower. Animal shelters and veterinary clinics are very aware of the consequences of missing an implanted microchip, and take extra measures to determine if a microchip is present. Universal scanners are becoming more available, and these solve the challenge of detecting different microchip frequencies.
