All about microchips

During our recent hiatus from the status quo, many fellow DC residents added a puppy, adopted dog, kitten or cat to their family. This is an exciting time and it is imperative that we do all we can to keep them healthy and safe. One component is identification with an implanted microchip. Microchips are a permanent identification system, which can help assist returning your pet if lost. 

What is a microchip?

Microchips are small solenoids, aka radio-chips, encased in an inert glass tube, which is implanted beneath she skin of your pet. There is no battery or electrical components and the chips are the size of a grain of brown rice. They are activated by a radio scanner which is passed over the pet, providing the scanner with an unique identification number. it does not act as a GPS device and does not provide any tracking for your pet.

What information is on a microchip?

Programmed into the actual chip – not much. Usually a 15 digit number (ISO chips) or a combination of letters and numbers. 

What is the procedure to implant a microchip?

Getting a microchip is similar to receiving a vaccination, albeit with a bit larger needle. The needle is inserted by a trained individual beneath the skin, usually between the shoulder blades. The chip can be implanted during a regular veterinary visit, but most often, it is done at the time of spaying or neutering. There is minimal bleeding and usually little to no discomfort once the injection is given. You will be asked to fill out a form with your contact information. This data is entered into the registry maintained by the manufacturer of your pet’s chip.

Is there more than on kind of microchip?

Yes. There are several different microchip frequencies and combinations of letters and / or numbers. The two main radio wave frequencies are 125 kiloHertz (kHz), 128 kHz, and 134.2 kHz. Most microchip scanners are able to read both frequencies. The standard chip used most frequently is an ISO 15 digit 134,2 kHz chip – this chip is required for most international travel, especially to Europe and Asia. We at District Veterinary Hospital use the ISO chip exclusively.

If my pet is lost, how does a microchip help?

A lost pet is usually presented to a veterinary hospital or animal control agency. Usually the first thing they do, aside from looking at any tags, is take a scanner and look for a chip. If located, the chip number is entered into the registry, and so long as there is accurate information, the pet can be reunited with its person. The registry maintains the wren’s contact information and will provide it to the agency who has the pet or, will contact the lost pet’s owner directly. 

Do chips really work?

A 2009 study published in the Journal of the American Veterinary Medical Association demonstrated that lost dogs without a chip only made it home 22% of the time, whereas those with a chip are reunited more than 52% of the time. The numbers are more stark in cats: 1.8% and 38.5%, respectively. Chips do work! 

Are there different chip registries?

Yes, each manufacturer maintains their own, but the microchip scanner usually dictates which registry to contact. When a lost pet is scanned, the manufacturer name and the chip number are displayed. To make finding the paper register easier, the American Animal Hospital Association, of which District Vet is a member, maintains This website will direct any user who enters a microchip number from a participating company to the proper database. 

What do I have to do to maintain the chip?

it is imperative that the information in the microchip manufacturer’s registry be accurate and complete. If you move or change your phone number, the company must be contacted. Most of the commonly used chips in the US have easy updating tools for this information. A chip is useless if the information in the database is inaccurate or incomplete. About a week or two after your pet is chipped, check the database to assure that this information is correct. At your pet’s annual veterinary visit, if time allows, ask your vet to check to be sure the chip is still working and in the proper spot. Very rarely, a chip will fail to respond. 

Can my pet have more than one microchip?

Yes – we frequently see this with world-traveling pets. Recall that most countries require the 15 digit ISO chip, but many shelters in the US have long used a non-15 digit chip. it is ok to have a second chip implanted, but it is imperative that you maintain accurate information in the databases of both chips! You never know which chip will be read first if your pet is lost. 

Why is there more than one type of chip?

This is America and we are not the greatest at standardization. Think capitalism, competition and the like. 

Are there any problems with microchips? 

Chip problems are thankfully very rare. Some people have raised concerns about tumors around microchips – this concern has not been found to be significant and only a scant few cases out of millions of chips have been reported. Rarely implantation of a chip can result in a localized infection – similar to almost any type of injection. These can be readily managed. Occasionally a microchip will slowly migrate from its implantation area to some place more distant. This usually does not cause any impact to the pet, but it may make finding the chip with a scanner more challenging. 

I just adopted a pet from the shelter, shat should I do concerning the chip?

First, be sure to register the chip to you! Second, have your veterinarian scan the chip and compare it to the number that you registered. Shelters do good work, but sometimes chip numbers can be confused. We at District Vet have seen this a number of times over the years – an adopter was given one microchip number, but it does not match the one given to the pet. We have also found that some pets already had a chip and now have two! And you must register both chips. 

Should I still have a collar with tags on my dog or indoor/outdoor cat?

Yes, most definitely. A collar is instant identification. A chip should be considered a supplement to a collar. 

Microchips are an integral part of pet identification. They are safe and very effective. We here at District Vet encourage all puppy and kitten parents to have their pet chipped at spay / neuter, or sooner. Chips work and can help bring home a lost pet quickly and safely.

Dan Teich, DVM

Medical Director, District Veterinary Hospitals

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