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Microchip implant (animal)

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Microchip implant in a cat.

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

The use of externally attached microchip devices such as RFID enabled ear tags (piercings rather than implants) is another, related method commonly used for identifying farm and ranch animals other than horses. In some cases the external microchips may be readable on the same scanner as the implanted style.

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 using microchip identification products 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. Animal control officers are trained and equipped to scan animals.

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.

Several countries require a microchip when importing an animal to prove that the animal and the vaccination record match. Microchip tagging may also be required for CITES-regulated international trade in certain rare animals; for example, Asian Arowana are so tagged, in order to ensure that only captive-bred fish are imported.

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 veterinarian selects a microchip from their stock, makes a note of that chip's unique ID, and then inserts the chip into the animal with a syringe. The injection requires no anesthetic.
  • 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 a registry keeper to be entered into its database. Depending on regional custom, selected chip brand, and the pet owner's preference, this registry keeper might be the chip's manufacturer or distributor, or an independent provider.[1] In some countries a single official national database may be used. After receiving a registration fee, the registry keeper typically provides a 24-hour, toll-free telephone service for pet recovery, good for the life of the pet.
  • 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 along with a certified registration certificate that can be sold/transferred with the pet. This ensures proper identification when an animal is sold or traded. A microchipped animal being sold or traded without a matching certificate could be a stolen 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.

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 coil inductor, or a core of ferrite wrapped in copper wire; and a capacitor. The silicon chip contains the identification number, plus electronic circuits to relay that information to the scanner. The inductor acts as a radio antenna, ready to receive electrical power from the scanner. The capacitor and inductor act as a tuner, forming an LC circuit. The scanner presents an inductive field that excites the coil and charges the capacitor, which in turn energizes and powers the IC. The IC then transmits the data via the coil to the scanner.

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

Cross-compatibility and Standards Issues

For years, questions of controversy have surrounded each of the four common microchip types (also known as transmission protocols or standards) used in pets, to the point that especially in the U.S., some pet owners may have delayed getting the implant done for fear of getting the wrong type.

Increasingly, conscientious vets and especially shelters in the U.S. are making it standard practice to scan for all four common pet-chip types, enabled by the long-awaited availability of four-protocol scanners that do it all at once. (Although apparently no law requires them to scan for even one type before disposing of an animal.) The various issues of debate still have importance, however, as the pet owner does still have a choice of the four types.

  • The ISO Conformant Full Duplex type is the pet chip type with the most international acceptance, being common in many countries including those of Europe since the late 1990s, and now widely adopted in Canada. It is one of two chip protocol types (along with the "Half Duplex" type sometimes used in farm and ranch animals) which conform to International Organization for Standardization, or ISO, standards 11784 and 11785. To support international/multivendor application, each of these chips contains either a manufacturer code[2] (99 manufacturer codes from 900 to 998 are supported.) or a country code (Values below 900 are assigned as country codes.) along with its main identifying serial number.[3] In the U.S., the distributing organizations that introduced this type of pet chip have faced controversy. When 24PetWatch.com in 2003 and more famously Banfield Pet Hospitals in 2004 began distributing them, many shelter scanners in use couldn't read them. (Some still can't; asking local shelters about this may be a good idea even today.) At least one of the Banfield-chipped pets was discovered to have been needlessly euthanized,[4] and Americans debated the cause. Specifically, did this happen because "foreign" chips were sold to unsuspecting pet owners, or because scanners which were passed off as a Shelter-Grade product couldn't cope with "internationally standardized" chips? Or maybe both? On June 30, 2009, an alert Editor reported being told by a HomeAgain manager that U.S. HomeAgain would start distributing the ISO chip type exclusively as of July 2009.[5] HomeAgain.com has been requested to confirm or deny this in its FAQ[6] file. If true, the tip would be noteworthy because, although ISO capable scanners were more common in the U.S. by 2009, HomeAgain's own vet and shelter scanners distributed from 1995 through most of 2005 are still blind to these chips, and no generally advertised recall/update program for these old scanners had been implemented. (Back in 2004, Banfield Hospitals were widely criticized for their ISO chip program, but Banfield never distributed a chip that was unreadable on the Banfield-distributed scanners.)
  • The Trovan Unique type is another pet chip protocol type used in U.S. pets beginning in 1990[7]. Then, due to patent problems, Trovan's implanter device was withdrawn from distribution in the United States and they became uncommon in U.S. pets, although Trovan's original registry database "infopet.biz" remained in operation. In early 2007, the American Kennel Club's chip registration database service, "akccar.org", which had earlier been the authorized registry for HomeAgain brand chips made by Destron/Digital Angel corp., began distributing Trovan chips with a different implanter. These chips are read by the Trovan, HomeAgain (Destron Fearing), and Bayer (Black Label) readers. Despite multiple offers from Trovan to AVID [8] to license the technology to read the Trovan chips, AVID continues to distribute readers that do not read Trovan or the ISO compliant chips.
  • A third type sometimes known as "FECAVA" type or "Destron" type[9] is available under various brand names. These include, in the U.S., "Avid Eurochip", "Avid TravelChip", the common current 24PetWatch chips, and HomeAgain chips distributed before July 2009 unless ISO chips were requested. HomeAgain chips of this type have 10 digit hexadecimal chip numbers. On request, U.S. 24Petwatch now can supply the true ISO chip instead. This "FECAVA" type is readable on a wide variety of scanners, and has been less controversial, although its level of adherence to the ISO standards is sometimes exaggerated in some descriptions.[10][11][12] The ISO standard has an annex (appendix) describing three older chip types considered worthy of legacy support by scanners, and a 35-bit "FECAVA"/"Destron" type is one of them.[13] The common Eurochip/HomeAgain chips don't really agree with the annex description perfectly, although the differences might be considered overlookable by some.[14] But the ISO standard also makes it clear[15] that even chips (like the Trovan Unique chip) that do match one of the descriptions in the Annex are not "conformant"; only its 64-bit "full-duplex" and "half-duplex" types are "conformant". More visibly, the "FECAVA" type can't fit the ISO standard's required country codes or manufacturer codes. These chips, when implanted in traveling pets, may possibly be accepted by authorities in many countries where ISO chips are the norm, but not those that require literal ISO conformance. (France is an example mentioned by one reference.[16])
  • Finally, there's the AVID brand Friendchip type, which is peculiar due to its sometimes misunderstood encryption characteristics. The simple fact that a cryptographic feature is provided in a chip would not necessarily be unwelcome; few pet rescuers or humane societies would object to a chip design that outputs an ID number "in the clear" for anyone to read, and, in addition, has authentication features for use by scanners that know how to use them, for detection of counterfeit chips. But the "Friendchips" have been found lacking in actual authentication features, and rather easy to counterfeit well enough to fool the AVID scanner. Although there's no authentication encryption involved, there is obfuscation encryption, meaning decryption secrets are needed, to convert what the chip transmits into its original label ID code. Well into 2006, scanners containing the secrets were provided to the U.S. market only by AVID and Destron/Digital Angel Corp.; Destron/Digital Angel put the decryption feature in some, but not all, of its scanners possibly as early as 1996. (For years, typically its scanners distributed to shelters through HomeAgain had full decryption, while many sold to vets would just flash a message that an AVID chip had been found.) And well into 2006, both of these were resisting calls from consumers and welfare group officials to bring scanners to the U.S. shelter community combining AVID decryption capability with full ability to read ISO pet chips. Some complained[17] that AVID itself had long marketed combination pet scanners (compatible with all common pet chips except possibly Trovan) outside the U.S., and by keeping such technology out of the U.S., it could be considered partly culpable in the missed-ISO chips problem others blamed on Banfield.[18] In 2006, the European manufacturer Datamars, a supplier of ISO chips used by Banfield and others, gained access to the decryption secrets, and began supplying scanners using them to U.S. customers. This "Black Label" scanner was the first four-standard full-multi pet scanner in the U.S. market. Then later in 2006 Digital Angel Corp. announced[19] it would supply a full-multi scanner in the U.S.,[20] and finally in 2008 AVID itself announced[21] one also, although AVID's is still uncommon in the field as of April 2009. Trovan also got the technology somehow along the way, by 2006 or earlier, and now provides it in triple-standard (lacking full ISO support) scanners distributed in the U.S. by AKC-CAR.

One question yet to be answered is whether the root cause of missed chip read problems in the U.S. was ever really an "incompatible frequency" issue, rather than just a case of generally inadequate scanners and chip manufacturers obfuscating their chips against the pet finder's attempts to read them. Much literature in print accepts dogmatically the supposed fact that ISO conformant chips operate at 134 or 134.2 kilohertz, and that the older types operate at 125 kilohertz (128 kilohertz for Trovan) and that this is their defining difference and the reason the "foreign" chips were hard to detect. But in fact, all the pet chips operate slaved to the frequency of the scanner. No reliable source has published tests showing whether the original Banfield-distributed ISO chips, if forced by an otherwise-unbiased multi-protocol scanner to operate all the way down at 125 kilohertz, have any poorer readability than for example, AVID Friendchips, which should work optimally at that frequency. (The ISO's choice to specify a different center frequency of 134.2 kHz may have been ill-advised, but if real specimens perform well in a 125 kilohertz-only test, can it be correctly said that they're not 125 kilohertz microchips?)

Banfield Pet Hospitals have for some time advocated and practiced double chipping with both ISO and "FECAVA" type chips, and apparently continue this even after the widely-publicized warnings about the small complication risk that comes with each chip. A non-medical complication of having multiple chips for any reason is that, since typical shelter scanners stop scanning after finding one chip,[22] and "Which one" can't be predicted, all of an animal's chip numbers need to be kept on file and address-updated with an appropriate database keeper for life. Presumably Banfield's enrollment forms have a space for "second chip number." The on-line enrollment forms of most registries could use some improvement in this regard. For best protection, the owner of multi-chipped pet may want to have each chip separately enrolled in its most customary or manufacturer-provided registry.

Scanner Compatibility Table for Chip Types Used in Pets
Expected Results for chip type
(OK=Good read
NR=No read
DO=Detect Only with no number given
OMT=Open Microchip Technology code given, requires translation)
Scanner to Test ISO Conformant Full Duplex chip (including HomeAgain distributed after July 2009) AVID Encrypted "FriendChip" U.S. HomeAgain (pre July 2009), AVID "Eurochip/Travelchip", or FECAVA "Trovan Unique" and Current AKC CAR chips
Minimal ISO Conformant Scanner OK NR NR NR
AVID Basic U.S. Scanner[23] NR OK NR NR
AVID Deluxe U.S. Scanner NR OK OK NR
AVID Universal Scanner sold outside U.S.[24] OK OK OK NR Assumed
AVID MiniTracker Pro Scanner announced August 2008[25] OK OK OK Announcement implies OK
Various vintages of U.S. HomeAgain "Universal" Shelter Scanners by Destron/Digital Angel Corp. NR,DO, or OK OK OK Possibly all OK
Typical Destron/Digital Angel Corp. U.S. Vet's scanner pre-2007

[26]

NR DO OK DO
Trovan LID-560-MULTI per mfr. specs on Web[27] OK OK OK OK
U.S. Trovan scanner per AKC-CAR Web Site[28] DO OK OK OK
Original 2006 Datamars Black Label Scanner[29] OK OK OK OK but Reliability Questioned
Datamars Black Label Scanner "classypets" model[30] OK NR or DO? OK OK but Reliability Questioned
Banfield-Distributed 2004-2005 Vintage Datamars Scanners OK Possibly all DO OK Possibly all OK but Reliability Questioned (Undocumented Feature)
Datamars Minimax and Micromax[31] OK NR NR NR
Typical Homemade Scanner[32] OK OMT OK OK

(For users requiring Shelter-Grade certainty, this table is not a substitute for testing the scanner with a set of specimen chips. One study[33] cites problems with certain Trovan chips on the Datamars Black Label scanner. In general the study found none of the tested scanners to read all four standards without some deficiency. The study predates the most recent Digital Angel and AVID scanners, however.)

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 reference.[34] 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 either requires two people (an avian veterinarian and a veterinary technician), or general anesthesia is administered.

Animal species

Many species of animals have been microchipped, including cockatiels and other parrots, 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.

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. [35] 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. [36]

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. [37]. Farm dogs were exempted from microchipping in an amendment to the legislation passed in June 2006. [38] A National Animal Identification and Tracing scheme in New Zealand is currently being developed for tracking livestock.

Australia has a National Livestock Identification System.

The National Animal Identification System is used in the United States. (It is applicable to farm and ranch animals rather than dogs and cats, and in most species other than horses, an external eartag device is typically used rather than an implant microchip. Eartags with microchips or those having only a visible stamped number can be used; either way, the 15 digit numbering scheme of the ISO type microchips is followed, using the U.S. country code of 840.)

Criticism

RFID chips are used in animal research, and tumors at the site of implantation have been reported in laboratory mice and rats.[39] Noted veterinary associations[40] responded with continued support for the procedure as reasonably safe for cats and dogs, pointing to rates of serious complications on the order of one in a million in the U.K., which has a system for tracking such adverse reactions and has chipped over 3.7 million pet dogs.

See also

References

  1. ^ In the U.S., AVID is an example of a manufacturer that also provides a registry, HomeAgain is an example of a distributor (of microchips made by Digital Angel) that operates a registry, and The American Kennel Club Companion Animal Recovery Corp., the nation's largest not-for-profit pet recovery service which has been in business since 1995, is an example of a registry that, for a time in 2005–2006, wasn't even affiliated with a chip distributor, but since 2007 has distributed the Trovan chip in the United States. HelpMeFindMYPET is an example of an independent provider in Canada, the United States, and Mexico.
  2. ^ [ http://www.service-icar.com/manufacturer_codes/Manufacturers_DB/manufacturer_codes_main.asp List of Manufacturer codes].
  3. ^ For display, typically three digits of country/manufacturer code are prefixed to twelve digits of the serial to make a 15-digit numeric string.
  4. ^ Pet's Death Rekindles Electronic ID Debate in JAVMA News.
  5. ^ Editor Therealmjfox's Conversation with HomeAgain district manager, June 2009.
  6. ^ HomeAgain.com FAQ file.
  7. ^ Trovan Chips Adopted by Los Angeles in 1996.
  8. ^ http://www.rfidnews.com/avidopenletter.html
  9. ^ Although an actual matching descriptive specification from the Federation of European Companion Animal Veterinary Associations, or one from Destron Corporation, remains illusive.
  10. ^ "B" Country List (Search for "Home Again microchips are ISO compatible" in the text.)
  11. ^ ISO Standards Discussion (Search for "as compliant" in the text.)
  12. ^ The TRAVELchip Single (Search for "Complies with" in the text.)
  13. ^ ISO Standards Combined Text ("FECAVA" discussion starts on page 16 of the PDF file.)
  14. ^ The differences would be obvious and surmountable to someone having a specimen of the "FECAVA" chips and trying to make a scanner for them, to the extent that the Annex is still quite useful to him. (The actual "FECAVA" chip's frequency-modulated signals are completely backwards/inverted from what the Annex calls for.)
  15. ^ This is found in clauses 2 and 6 of ISO 11785; the two actual conformant 64-bit types are described in clauses 6.1 and 6.2.
  16. ^ Readable Microchips & Microchip Scanners (Search for "France" in the text.)
  17. ^ Pet's Death Rekindles Electronic ID Debate in JAVMA News (Search for "best" in the text.)
  18. ^ Few of the petitioners bothered to ask AVID to add Trovan-chip compatibility at that time, as these chips would remain uncommon and obscure until 2007 in the U.S.
  19. ^ APHIS Comment Submission from Digital Angel Corp (page 2, item 4 in the referenced .doc file.)
  20. ^ In addition to its current scanners with full support for ISO full duplex chips, and maybe ten years production of earlier scanners with no ISO support, Destron/Digital Angel Corp. is also reported to have made in-between models circa 2006, one that gives a detection indication but no number for ISO chips, and one model that gives either simple detection or full number readout depending perhaps on the chip's manufacturer or some other factor. These models may be hard to discern without a lot of specimen chips; a software update may be available.
  21. ^ Avid Announces New Scanner to Reunite More Lost Pets with Their Families.
  22. ^ It might be argued that Shelter-Grade scanners shouldn't do this.
  23. ^ Descriptions of AVID Scanners (Search for "only the AVID" in the text.)
  24. ^ Test Results from American Humane (Search for "in use in canada" in the text.)
  25. ^ Avid Announces New Scanner.
  26. ^ Test Results from American Humane (Search for "unless vet is with a shelter" in the text.)
  27. ^ Trovan Multi Scanner specs (Apparently applies to models sold outside U.S.)
  28. ^ Using The AKC-CAR Multi-System Pocket Scanner (U.S. Model says "Detect Only" on ISO chip type.)
  29. ^ Datamars Multi Scanner specs.
  30. ^ Datamars Multi Scanner specs.
  31. ^ Datamars Scanner Descriptions.
  32. ^ Software for Homemade Scanners- Chip Type Listing.
  33. ^ Nov. 2007 Scanner Evaluation from EID Limited.
  34. ^ Microchip Implantation Sites (World Small Animal Veterinary Association).
  35. ^ WSAVA - Australian Microchip Standard
  36. ^ Entering Japan: Dogs & Cats.
  37. ^ The Year of the Dog War (New Zealand Herald).
  38. ^ Farm Dogs Exempted from Microchipping
  39. ^ Chip Implants Linked to Animal Tumors - washingtonpost.com
  40. ^ Position Statement from World Small Animal Veterinary Association. 
*A1 ID Systems: Manufacturer of microchip identification for animals.
  • PIT Tags used on Peregrine Falcon Research
  • "Injunction on Microchip Sales". Pet Age. January 2005. Retrieved 2009-01-03.
  • Microchip Frequently Asked Questions
  • Petlog
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