Unlike our furry friends the dog and cat, turtles and tortoises (known collectively as "chelonians") aren’t quite suited to wearing collars bearing ID tags.  In the past chelonian enthusiasts have tried to establish forms of identification for their turtles and tortoises through various methods.  Microchips (also know as transponders, PIT tags, or microchip transponders) such as the Bayer ResQ brand, provide a more long-lasting and reliable form of identification.

Most microchips are about the size of a grain of rice.  This small size makes them easy to inject into muscles or beneath the skin of all but the smallest chelonians.  They provide durable and easy identification.  The microchips are designed to have an operating life of over 25 years, however most companies guarantee the microchip for the life of the animal.

Each chelonian that is microchipped is entered into a data base.  When your pet is scanned by a microchip reader, its unique identification number will appear on the reader’s screen.  A simple phone call allows the animal’s number to be linked with ownership information or, if you prefer a little added privacy, with the veterinary hospital that inserted the microchip.

Most microchips (98%) used in the US are of the 125 kHz frequency variety which is now considered the standard of care.  However, all microchip and microchip scanners are not created equal.  Other microchip frequencies are out there, such as 134.2kHz and 128kHz.  The vast majority (80%) of scanners will read ONLY the 125 kHz microchips.  The bottom line is that when picking a microchip, choose one that is of a frequency that can be read by the greatest number of veterinarians, shelters, and animal control agencies, which is the 125kHz variety.   At Arizona Exotic Animal Hospital we use Bayer ResQ microchips which can be read by any ISO-compliant scanning device worldwide (www.iso.org)

What are the advantages of microchipping chelonians?

• Correctly identify individuals in large groups
• Simplify record keeping
• Proof of ownership
• Increased chance of retrieval of a lost chelonian
• Theft prevention/recovery
• Disaster preparedness
• Online sales
• Added value of animals

STANDARD MICROCHIP SITES FOR CHELONIANS

• Left hindlimb
• The microchip is placed in the subcutaneous tissues.  The injection site is then closed with tissue glue.
• Midline sub-plastron.  The needle is inserted under the tail and just above the caudal edge of the plastron and advanced into the connective tissue between the pubis and the plastron.
• Requires limited aftercare.
• May be more advantageous for semi-aquatic turtles due to the quick return to the water.  However, the turtle must be dry docked for at least 24 hours post implantation. 

POTENTIAL COMPLICATIONS ARISING FROM MICROCHIP PLACEMENT

• Abscess formation
• Risk of chip loss
• Chelonian skin is inelastic and the insertion site remains open when a proper closure is not preformed.
• Infection
• Even with appropriate technique a small number of chelonians develop an infection at the insertion site.
• Chip migration
• Migration into the coelomic cavity may cause peritonitis.
• Possible damage to blood vessels and nerves
• This can occur in either the ventral or dorsal aspect of left rear leg with improper placement.
• Hemorrhage
• More common with intramuscular chip placement than with subcutaneous insertion; it is usually easily controlled.

CONSIDERATIONS

• Hibernating species like Sonoran Desert tortoises
• The best time to microchip these animals is in the spring after recovering from hibernation.
• If the microchip is implanted close to the chelonian’s hibernation period it is recommended to keep them awake for at least 6 weeks so the site can be monitored.
• Non-hibernating species
• Can be microchipped at any time of the year
• Sedation may be needed
• Some animals may require sedation for this procedure in order to gain access to the rear leg.  Excessive force to extend the back leg can damage chelonian bones and ligaments.
• Size
• Although microchips can be successfully placed in chelonians of various sizes, it may be easier with a greater chance of success and less change of complications if placed in larger animals.

AFTER THE MICROCHIP IS PLACED

Ensure the chelonian has a clean habitat for several days after the implantation.  If sutures are used to close the injection site (vs. tissue glue) these can be removed after 4 weeks.  Over the next few weeks continue to monitor the site for signs of infection (swelling, redness, heat, or discharge), and test scan the microchip to ensure it has remained in its proper location and has not migrated.  Semi-aquatic turtles should be dry docked for at least 2 days post-injection (for rear leg placement) and good water quality is crucial to prevent infection.

This procedure is not for everyone, there are serious complications that can arise from implanting microchips, as stated above.  Owners must make well informed decisions about chip implantation, and they must weigh all the benefits and the negative aspects of this form of identification before pursuing microchipping.  There are certain instances where microchips could play a valuable role, but each case needs to be assessed on an individual basis to determine if microchipping's benefits out way the risks for that particular chelonian.

Written by Dr. Kristy Ramella

Copyright 2009
Kevin Wright and Jay Johnson
Arizona Exotic Animal Hospital, LLC
744 N Center Street
Mesa, AZ 85203
info@azeah.com