Introduction
Outbreaks of neurologic Equine Herpes in the United States, combined with reports of natural disasters such as Hurricane Katrina, point to the continued need for a reliable means of equine identification. Diseases and disasters strike with little or no warning and it’s important for owners to know that their animals are protected. Proper identification, and the ability to rapidly trace a disease outbreak to its source, is necessary to protect the health of individual horses and the U.S. equine industry as a whole.

As we have seen with equine influenza in Australia and equine herpesvirus myeloencephalopathy in the United States, an animal disease outbreak can restrict horse movements, sales, shows and commerce. When a disease or a disaster strikes, fast action coupled with a certain source of identification is the surest means to protect animals and limit disease spread or loss.

Forms of Identification
In the United States, early equine identification was simply a sketch or a written description of the animal. Hot iron branding was introduced by Spanish settlers in the early 1800s and adopted by ranchers in the western U.S. Lip tattooing was adopted in the late 1800s. Today, we have a modern option to safely and reliably identify horses – electronic identification (EID).

EID utilizes microchips, each about the size of a grain of rice, that are permanently implanted in the nuchal ligament on the horse’s left side, in the middle third of the neck, halfway between the ears and withers. Field trials have shown the transponders are easy to implant with a 12-gauge needle and can be safely implanted with little or no irritation.  It is recommended that they be placed by a veterinarian. These microchips, also called injectable transponders, satisfy the need for permanent, easily proven equine identification. The injectable transponder uses radio frequency (RF) technology and is encoded with an animal identification code.

840 Injectable Transponders
It is recommended that horse owners purchase ID devices that are approved by USDA as compliant with the National Animal Identification System (NAIS). While NAIS is a voluntary program, the use of an NAIS-compliant 840 injectable transponder will greatly enhance the ability to rapidly and efficiently trace horses in the event of a disease outbreak. The transponder is encoded with the animal identification number (AIN), the standard for identification of individual animals in NAIS. The AIN is unique 15-digit number starting with 840, the country code for the United States. The remaining digits provide the unique identification number for each horse. The AIN for each animal is then linked to the location the animal was kept when it was identified through a premises identification number (PIN). This allows for easy traceback to the premises of origin.

The 840 injectable transponder offers horse owners flexibility in its uses. AIN and PIN information from the injectable transponder can be used on Certificates of Veterinary Inspection (CVI) and EIA (Coggins) tests. This official paperwork supports animal health programs and other equine industry activities, including domestic and international movement of horses. Some breed registries are also accepting 840 injectable transponders as an official form of identification.

Requirements for the NAIS-compliant injectable transponder follow the recommendations of the Equine Species Working Group (ESWG) and comply with International Organization of Standards (ISO) 11784 and 11785 for radio frequency identification. The ESWG is the horse identification task force recognized by the USDA.  It includes 35 representatives of the horse industry and animal health officials and is co-chaired by Dr. Jim Morehead (American Association of Equine Practitioners) and Dr. Billy Smith (American Quarter Horse Association). 

Before an NAIS-compliant injectable transponder can be obtained and implanted, the premises where the horse is located must have a PIN. Obtaining one is easy and free.  You can fill out a short form available from the State veterinarian’s office or from the department of agriculture in the State where the premises is located. The information requested is simple and includes the address of your property, as well as the types of animals you keep. Once you receive your PIN, you can purchase AIN injectable transponders for your horses. Working together, the AIN and PIN provide you with the assurance that if there is a horse health event near your horses, animal health officials can find and alert you. 

Looking to the Future
With technology growing at a rapid pace, 840 injectable transponders are a practical method of identifying horses and other animals that do not enter the food chain (such as llamas and alpacas). This modern means of identification can complement more traditional methods including the logging of natural markings, age, gender, breed, hair coat color, and existing human made markings. As more businesses and veterinarians adopt computers for field use, 840 injectable transponders will quickly move to the forefront of equine identification. The ability to use NAIS and 840 injectable transponders to help prevent disease spread and provide prompt identification in the event of a disaster will be an asset to the United States equine industry.

Contributed By: Tim Cordes, DVM