We get many questions about microchips and how they work, so instead of trying to cram it all into the FAQ page, microchips get their own dedicated page. If you have questions not covered here, please email them to Dr. Adams; new material may be added to this page as more questions come in.
A microchip, or radio-frequency identification chip, is a small device (about the size of a fat grain of rice) implanted into the subcutaneous tissue via a hollow needle. This device is coated with a biologically inert substance to prevent chronic inflammatory responses to the presence of the chip. It stores an alpha-numeric code, which can be recalled by passing a scanner of appropriate frequency near the chip. This code is associated in a national database with the pet's information and owner contact information, so that if the pet is ever taken to a shelter, rescue, or properly equipped veterinary clinic they can be returned to the owner.
At this time, microchip identification is the most efficient and reliable method of identification for pets. Collars or harnesses can be slipped off, removed, or snagged. Tags can be chewed up, or lost. Breed association tattoos are still used by many breeders, but finding owner information through those requires that the shelter be able to figure out with which breed association the dog is registered; sometimes a daunting task given the variety of breed associations across the country. Because the information is available to any shelter or any quality veterinary clinic in the country, it doesn't matter if the pet is lost while traveling.
Millions of dogs and cats are euthanized in shelters every year in this country alone because the owners cannot be found. The National Council on Pet Population Study and Policy conducted a survey in 1997 of 1,000 shelters. In the shelters that replied to the National Council's survey, 4.3 million animals were handled. Roughly 64 percent of the total number of animals that entered these shelters were euthanized -- approximately 2.7 million animals in just these 1,000 shelters. Only 15 percent of dogs and 2 percent of cats that entered surveyed shelters were reunited with their owners. The difference in return of cats to owners compared to dogs is attributed to the generally greater lack of identification on cats. As you can see, any form of identification can greatly improve your pet's chances of being returned if they somehow get lost!
Can the microchip be GPS or satellite tracked?
No, the microchip itself has no power source (think how tiny the battery would have to be!), so it cannot emit a signal to be picked up by a GPS device or satellite. Reading" the chip requires that a scanner which emits radio waves of the correct frequency, be passed in close proximity to the chip. The waves bounce back to the scanner from the chip, revealing the chip's specific code. Most scanners are small, hand-held devises which operate on AA or C sized batteries. To read properly, the scanner must be close to the chip (within 2 - 6 inches) and moved slowly. If the pet is moving rapidly or the scanner is swept too swiftly across the pet, it will miss the returned radio signal.
There are devices which will send out a signal to be tracked from a distance, but these are typically small boxes several inches across, which are affixed to a collar. They are sometimes used for hound dogs trailing game, or for wildlife movement studies. These devices are not permanent; they can be lost or damaged, and have a limited power life, as they rely on batteries included in the collar.
Does implantation hurt? And does my pet need to be anesthetized for implantation?
Yes, and no. Implantation is done through a needle, which has to be large enough to surround the chip. Depending on the brand of chip, this may be a 12 or 14 gauge needle; for comparison, that's about the size of belly button ring piercing. For a small dog or cat, that could obviously be uncomfortable. However, implantation is very quick, and typically anesthesia is not required. For smaller pets such as ferrets and birds, we may recommend anesthetizing for implantation. Certainly if we are anesthetizing your pet for some other reason, such as neutering, we can implant the microchip at the same time, so there will be no associated pain.
What are the potential side effects of microchip implantation?
As with any needle stick, there may be some bleeding at the injection site. This is usually only 1 - 3 drops of blood, and quickly stops with pressure. Chips for implantation are designed not to cause inflammatory reactions, so we do not expect soreness or swelling at the implantation site in most cases. Rarely, microchips may migrate through the tissue, ending up somewhere unexpected; this typically happens in the first 2 weeks following implantation, before the body's tissues heal around the chip and affix it in place. Because of this, it's a good idea to have your veterinarian verify that the chip is in an appropriate location on your next visit.
How long does a microchip last?
Because the microchip has no internal power source, it lasts indefinitely. It will not wear out or need to be replaced regularly the way medical or hormonal implants do.
How much does microchipping cost?
The cost varies depending on the brand of chip purchased and the clinic that implants it. At the Chewelah Veterinary Clinic, we charge $40 for implantation and registration. Many clinics do not include registration in their fee, so be sure to ask if calling around to compare prices. If the clinic does not cover registration for you, that may be an additional $15-25 after implantation. Updating your information should you move or sell/give the pet to someone else costs between $5 and $15 depending on the company the chip is registered with.
What if I don't get my pet's chip registered?
Until a microchip is registered by the owner, the manufacturer keeps it listed as dispensed to the clinic or shelter to which it was shipped. Thus, if we implant a chip in a pet, and you do not send in your registration, if that pet is taken to a shelter and scanned, the microchip company will provide the finder with our clinic's information. We do keep a list of what chips we implanted in which pets, so this should still result in contact with you. However it is highly recommended that you register the chip and provide your contact information as well as an emergency contact in case you cannot be reached. The more steps in tracking down a pet's owner, the more chances to miss a message or otherwise drop the ball.
Can a microchip be reused?
Not really. It would have to be extracted from one animal, then re-sterilized and possibly re-coated before implanting in a new animal. It is far easier and less expensive to simply use a new, sterile implant.
Can you take a microchip out? Or can I take it out at home?
Please do not attempt to remove a pet's microchip at home! For both your safety and the safety of your pet, this is an extremely bad idea. The chip is implanted into the subcutaneous tissue, so removal requires an actual surgical procedure. The chip must be precisely located, the animal anesthetized, and an incision made through the skin and subcutaneous tissue down to the chip, the chip extracted, and the tissue closed. As with any surgical procedure, there is a minor risk associated with anesthesia (of course we do our best to ensure the safety of every animal we anesthetize, but this is not something to do just because), and a risk of infection in the surgical site. Because the risks of adverse effects from a microchip are so low, the risks of anesthetic and surgery, while not great, are relatively greater than simply leaving an already implanted chip in place.