Microchip implant (animal)

From Wikipedia, the free encyclopedia

A microchip is an identifying integrated circuit placed under the skin of a dog, cat, or other animal. The chips are about the size of a large grain of rice and are based on a passive RFID technology.

Tattooing is another, older method for identifying animals.

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[edit] Uses and benefits

Microchips have been particularly useful in the return of lost pets. They can also assist where the ownership of an animal is in dispute.

Animal shelters and animal control centers benefit from microchipping by more quickly and efficiently returning pets to their owners. When a pet can be quickly matched to its owner, the shelter avoids the expense of housing, feeding, providing medical care, and outplacing or euthanizing the pet. Microchipping is becoming increasingly standard at shelters: many require all outplaced animals to receive a microchip, and provide the service as part of the adoption package.

In addition to shelters and veterinarians, microchips are used by kennels, breeders, brokers, trainers, registries, rescue groups, humane societies, clinics, farms, stables, animal clubs and associations, researchers and pet stores. Animal control officers are also trained and equipped to scan animals.

Several countries require a microchip when importing an animal, as a proof that the animal and the vaccination record belong together.

[edit] System of recovery

Effective pet identification and recovery depends on the following:

  • A pet owner either adopts a pet at a shelter that microchips some or all adoptee animals, or the owner with an existing pet brings it to a veterinarian (or a shelter) that provides the service.
  • The shelter or vet selects a microchip from their stock, makes a note of that chip's unique ID, and then inserts the chip into the animal.
  • Before sending the animal home, the vet or shelter performs a test scan on the animal. This helps ensure that the chip will be picked up by a scanner, and that its unique identifying number will be read correctly.
  • An enrollment form is completed with the chip number, the pet owner's contact information, the name and description of the pet, the shelter's and/or veterinarian's contact information, and an alternate emergency contact designated by the pet owner. (Some shelters or vets, however, choose to designate themselves as the primary contact, and take the responsibility of contacting the owner directly. This allows them to be kept informed about possible problems with the animals they place.) The form is then sent to the manufacturer of the chip to be entered into its database. This company typically provides not only the microchips, but a 24-hour, toll-free telephone service for pet recovery, good for the life of the pet.
  • Alternatively, the pet owner may enroll the pet and chip with one of several chip-supplier-independent registries of which the American Kennel Club Companion Animal Registry [1] is an example in the U.S. In some countries a single official national database may be used.
  • The pet owner is also provided the chip ID and the contact information of the recovery service. This is often in the form of a collar tag imprinted with the chip ID and the recovery service's toll-free number, to be worn by the animal.
  • If the pet is lost or stolen, and is found by local authorities or taken to a shelter, it is scanned during intake to see if a chip exists. If one is detected, authorities call the recovery service and provide them the ID number, the pet's description, and the location of the animal. If the pet is wearing the collar tag, anyone who finds the pet can call the toll-free number, making it unnecessary to involve the authorities. (The owner can also preemptively notify the recovery service directly if a pet disappears. This is useful if the pet is stolen, and is taken to a vet who scans it and checks with the recovery service.)
  • The recovery service notifies the owner that the pet has been found, and where to go to recover the animal.

Many veterinarians perform test scans on microchipped animals every time the animal is brought in for care. This ensures the chip still performs properly. Vets sometimes use the chip ID as the pet's ID in their databases, and print this number on all outgoing paperwork associated with its services, such as receipts, test results, vaccination certifications, and descriptions of medical or surgical procedures.

[edit] Components of a microchip

Microchips are passive, or inert, RFID devices and contain no internal power source. They are designed so that they do not act until acted upon.

Three basic elements comprise most microchips: A silicon chip (integrated circuit); a core of ferrite wrapped in copper wire; and a small capacitor. The silicon chip contains the identification number, plus electronic circuits to relay that information to the scanner. The ferrite -- or iron -- core acts as a radio antenna, ready to receive a signal from the scanner. The capacitor acts as a tuner, forming a LC circuit with the antenna coil.

These components are encased in special biocompatible glass made from soda lime, and hermetically sealed to prevent any moisture or fluid entering the unit. Animals are not affected physically or behaviorally by the presence of a chip in their bodies.

[edit] Cross-compatibility

Because microchips and scanners are manufactured by different companies, and different countries adopt their own standards, attempts have been made to establish a universal protocol that enables all microchips to be read by all scanners. This effort has not yet been successful. But making all scanners (including old scanners) read all chips is an unreasonable goal anyway. A modest goal might be, new scanners that read all chip types ever commonly used for pets.

In late 2005, the U.S. Congress (Search for "microchip" in [2].) directed the Animal and Plant Health Inspection Service (APHIS) to work on bringing about a "system of open microchip technology" with "universal reading ability." Many realized this should involve working to find a way to deal with the AVID "Encrypted" microchip type, because all the other kinds are already Open Microchip Technology by their design, requiring no secrets to decode. But instead, APHIS proposed a rule establishing one specific Open chip type as the standard for dogs and cats in certain circumstances. This was controversial, because the type selected (ISO 11784/11785) was one not widely supported by the infrastructure of scanners in the U.S. at the time. About 180 spirited comments submitted to the APHIS during a comment period ending in September of 2006 are archived at [3] regulations.gov. These are not accessible by URL, but can be found by a regulations.gov search, using docket number "APHIS-2006-0012" and specifying "All documents, open and closed."

The two companies which dominate the U.S. market -- AVID and HomeAgain -- both sell microchips which are optimized to operate at a frequency of 125 kHz. This allows the scanner of one manufacturer to detect the presence of its competitor's microchip -- even if it cannot actually decode the chip's encoded or encrypted ID. Some scanners manufactured by Digital Angel/Destron Corp. and distributed by HomeAgain for shelter use have for some time [4] been able to both detect and decrypt the AVID "encrypted" ID chip. Digital Angel/Destron Corp. seems to have been the first, after AVID itself, to join the group of manufacturers who have the secrets needed to recover the registration codes from these chips. Still, some of the Digital Angel/Destron models, (often those used by vets rather than shelters) may only flash an acknowledgment that an AVID chip has been found, with no number given. AVID's base scanner model circa 2006, however, doesn't even bother to give an indication of the presence of a chip of the type used by HomeAgain, even through no secrets are needed to fully decode these. A more deluxe AVID scanner model reads both kinds. [5]

But in Canada, Europe, Asia and Australia, most microchips for animals adopt a standard (11784/11785) set by the International Organization for Standardization, or ISO, specifying that chips operate at 134.2 kHz.

The idea that mere frequencies are a main component of the universal scanner problem may be disinformation from the "microchip wars." All the common pet chip types operate at the frequency used by the scanner as long as it's suitably close to its tuned frequency. A compromise excitation frequency can be used. On Page 8 of Entry 11 in the APHIS Comments archive, even AVID confirms that a compromise excitation frequency can be and has been used, mentioning 128 kHz, but implies that it's hopeless to achieve good performance with it. Others would say, more important than frequency is whether the scanner maker chooses to support all the published open protocols applicable to common pet chip types, and whether she has the secrets necessary to deal with obfuscation-encrypted chips. It has been suggested that the AVID "encrypted" chip has obfuscation encryption rather than authentication encryption, because although secrets are needed to build a scanner to extract its original label code, enough information to make a clone or counterfeit (indistinguishable from the original by the AVID scanner) can be gathered just by "listening" to it for a short time. An experimenter's project [6] has been offered illustrating this.

When Banfield began selling Crystal Tag microchips in the U.S. -- chips made by Switzerland-based DATAMARS, and following ISO standards -- not enough scanners were distributed to ensure that these chips (with their different frequency) could be detected. Customers were not aware that far fewer shelters and clinics were equipped to detect these chips than the 125 kHz chips.

Are patents the holdup on universal scanners? It has been reported in several sources[citation needed], that AVID holds patents on "125 kHz technology". The specific U.S. patent number purported to cover 125 kHz technology is generally absent in these. This article [7] might look like an appropriate citation for an AVID 125 kHz patent, up to the point where it identifies the frequency of the products found to infringe on three patents of AVID as... 134.2 kHz. Might one of these three patents preclude any possible universal pet scanner regardless of the excitation frequency used? This article [8] identifies the three patents. The first two patents listed are discussed only as covering "transponders," the implantable chips themselves, so they wouldn't be a problem for scanner designers. The third, number 5235326, [9] covers, along with some tag (transponder) claims, a wide variety of readers/scanners that contain something called "Mode Control Data" or use certain multi-step decoding methods. A universal single-frequency scanner that just listens simultaneously for all the common types of pet chips would seem not to need Mode Control Data or these multi-step methods, so it might be quite prudent for a scanner maker to not use them. Further applicable patent citations for this page would be welcome.

For those wishing to build an Open Microchip Technology scanner for all pet chip types, the numerous U.S. pets with the AVID "Encrypted" chip are a major obstacle. At least one Open Standards based work-around was submitted to the APHIS during its 2006 comment period. (Entry 137 in the Archive.) Some may consider such schemes untidy, but work-arounds may be the only option for those who want to build a scanner for obfuscation-type chips and aren't a member of the small monopoly-group, or perhaps "cartel," of those who have the decryption algorithm's secrets. This group has historically, through mid-2006 at least, not applied its secret knowledge to make scanners combining both obfuscation-type and ISO-type pet chip reading capabilities available in the U.S. Some people have complained (Search for "best" in [10]) that AVID itself sold such a device in other countries while claiming it wasn't good enough to sell at home. Digital Angel/Destron Corp. reportedly [11] [12] added ISO-chip detection capabilities, with no number readout, to its HomeAgain-distributed product only late in 2005. It is now (Entry 151 in the APHIS Comments archive) claiming to have plans for shipping universal units that will fully decode the ISO-chip in 2007. Even this belated change may be a reaction to recent (2006) additions to the group. This may include the European manufacturer Trovan, even though its decrypting [13] multi-scanner is little known in the U.S. More prominent may be the news that AVID's arch-rival Datamars seems to have gotten the secrets somehow and used them in its "Black Label" [14] scanner. This may be greeted as good news by some, but making a bigger group of secret-holders is a different thing from turning the chips into Open Technology chips by publishing their secrets. Spreading the extent of a monopoly does not equal establishing a "system of open microchip technology."

The industry seems to agree that before ISO chips are more widely distributed in the U.S., scanners that can read the chips should be widely distributed first, and a transition strategy should be in place.

[edit] Implant location

In dogs and cats, chips are usually inserted below the skin at the back of the neck, between the shoulder blades on the dorsal midline. Continental European pets may be an exception; they get the implant in the left side of the neck, according to one [15] reference. The chip can often be manually detected by the owner by gently feeling the skin in that area. It stays in place as thin layers of connective tissue form around the biocompatible glass which encases it.

Horses are microchipped on the left side of the neck, half the distance between the poll and withers, and approximately one inch below the midline of the mane, into the nuchal ligament.

Birds' microchips are injected into their breast muscles. Because proper restraint is necessary, the operation requires two people -- an avian veterinarian and a trained assistant.

[edit] Animal species

Many species of animals have been microchipped, including birds, horses, llamas, alpacas, goats, sheep, miniature pigs, rabbits, deer, ferrets, snakes, lizards, alligators, turtles, toads, frogs, rare fish, mice, and prairie dogs -- even whales and elephants. The U.S. Fish and Wildlife Service uses microchipping in its research of wild bison, black-footed ferrets, grizzly bears, elk, white-tailed deer, giant land tortoises and armadillos.

[edit] World-wide use

Microchips are not in universal use, but there are legal requirements in some jurisdictions, such as the state of New South Wales, Australia. Some countries, such as Japan, require ISO-compliant microchips on dogs and cats being brought into the country, or for the person bringing the pet into the country to also bring a microchip reader that can read the non-ISO-compliant microchip. [16]

In New Zealand, all dogs first registered after 1 July 2006 are to be microchipped. Farmers protested that farm dogs should be exempt, drawing a parallel to the Dog Tax War of 1898. [17]. Farm dogs were exempted from microchipping in an amendment to the legislation passed in June 2006. [18]

[edit] External links

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