Throughout much of the world, a standard recommended by the ISO that 134.2-kHz microchips be used for microchip identification of companion animals has been adopted as the preferred or sole standard. 1,2 This standard has been endorsed by the
implanted microchips. The implantation of a microchip can help a lost pet to be reunited with its owner. 3,4
In the past few years, there has been an increase in the number of pets implanted with microchips. Also, advances in medical technology have made
be to increase the use of microchipping, which provides a permanent and unalterable method for identifying pets.
While many leading veterinary and animal welfare associations support the ISO standard of microchip identification of companion animals
Although much attention has been given to the issues of microchip scanners and the various microchip frequencies available in the United States, little has been done to characterize the microchip registration process as it relates to reuniting
parts of the world include hot iron branding and microchip transponder injection. Hot iron branding is still widely used as a means of identification. The availability of microchip transponders has led to an ongoing discussion regarding whether hot iron
contact information at the time they were lost and only 7% had a microchip, compared with 43% of dogs with visible identification and 8% with a microchip. In Ohio, only 17% of 217 surveyed cat owners reported they use visual means for identifying their
, hygienic, and more rapid method of obtaining a temperature measurement in equids, provided that they are accurate, compared with temperatures obtained by use of rectal thermometers. In a single experimental study, 2 microchips were evaluated as thermal
Objective—To determine whether microchips used
for identification migrate after implantation in horses,
donkeys, and mules.
Animals—53 horses, donkeys, and mules.
Procedure—Twenty horses that had had microchips
implanted in the nuchal ligament at a veterinary teaching
hospital from 1996 through early 2000 were
included (group 1), and the poll-to-withers distance
and location of the microchip were determined, measured,
and recorded. Additionally, the poll-to-withers
distance was measured in 16 horses, 12 donkeys, and
5 mules (group 2), and microchips were implanted in
the nuchal ligament on the left side of the neck. Fortytwo
to 67 days after implantation, the location of the
microchip was determined, measured, and recorded.
Results—Microchips implanted in the nuchal ligament
≤ 4 years previously did not migrate. All
microchips were detected with a multimode identification
tag reader from the left side of the neck in the
midcervical region, and microchips were located at
the midpoint between the poll and withers for all 53
horses, donkeys, and mules.
Conclusions and Clinical Relevance—Microchips
implanted in the nuchal ligament ≤ 4 years earlier did
not migrate in horses. Microchips may be useful for
identification in horses. (J Am Vet Med Assoc 2003;
microchip with a temperature sensor has been developed for dogs and is currently marketed in Europe and Asia. To our knowledge, there are no published studies regarding accuracy or reliability of the subcutaneous microchip device for temperature
implanted microchip identification methods and Web sites devoted to finding and returning lost pets to their owners. However, the effectiveness of the various methods available for recovering lost pets has not been reported. The purposes of the study