Equine IdentificationBy Kentucky Equine Research Staff · October 26, 2006
There are a number of ways to describe or identify horses and to differentiate one horse from others that may be of similar appearance. Verbal descriptions, photographs, and drawings are a good place to begin. Many breeds and disciplines require brands or other permanent markings when a horse is registered or begins to compete. For instance, Thoroughbreds must have a unique number tattooed inside the upper lip before they are allowed to race. Microchipping is one of the most recent identification methods to come into popular use.
What's behind the recent emphasis on animal ID?
Outbreaks of bovine spongiform encephalopathy (mad cow disease) over the past several years have pointed out the importance of being able to trace the location and movements of a particular animal throughout its lifetime. While this is especially critical for animals that become part of the human food supply, positive identification can also be important for horses as well as for dogs, cats, and other animals that are kept as pets or for recreational purposes. As identification methods are developed for use in food animals, these techniques have also been applied to other species that may be involved in breeding, showing, competition, or sales.
Why is an ID important?
It's easy to understand why someone who breeds, shows, or sells horses would want to have an infallible method of identifying each animal, but how important is this concept to owners who have only a few horses that never leave the farm? The answer becomes obvious after a tornado, flood, or other natural disaster that results in farm animals wandering about the countryside. It took weeks following widespread hurricane devastation in the Gulf Coast states before many owners were able to track down and claim their horses from rescue centers.
Is my horse required to have a permanent ID?
At the present time, there is no nationwide requirement for permanent identification of horses in the United States. However, some individual states and equine registries require horses to have permanent identification. Regulations are different depending on the particular breed of horse.
What types of ID are available?
Branding is one of the oldest types of identification. Years ago, the mark or logo of a ranch was shaped into a branding iron which could be heated and applied to the animal's hip or flank area. When the burn healed, the resulting hairless scar remained visible for the life of the animal.
Freeze branding, where a similar metal template is cooled with liquid nitrogen and pressed onto the horse's skin, is a newer development. In some breeds, a small brand is applied to the neck below the mane, while other registries require a shoulder or hip brand.
Other identification methods involve scans of the retina or chestnut (night eye). A DNA analysis guarantees accurate identification, but is of limited usefulness when an immediate identification must be made.
In a recently developed technique known as microchipping, a small transponder is inserted just under the skin, leaving no visible mark. A hand-held scanner passed over the transponder displays a number unique to each horse.
What happens when a horse is microchipped?
A tiny transponder, which can be as small as a grain of uncooked rice, is injected under the skin using a sterile needle designed for this purpose. The standard position is in the nuchal ligament on the left side of the neck, just beside the roots of the mane and about halfway between the ears and the withers.
The outside of the chip is made from a type of glass selected for its biocompatibility. Because the glass casing is extremely smooth, there is some chance the chip could move from the injection site, especially if it is implanted in muscle tissue as was fairly common in past years. Modern transponders have a small polypropylene patch or band at one end. This substance allows fibrous connective cells to lock the transponder to the horse's tissue, preventing accidental migration.
Does microchipping hurt the horse?
The horse feels slight discomfort at the moment of injection, but the chip is painless once it is in place. Numerous studies have been performed on horses and other animals to investigate health effects of microchipping. No adverse reactions, either biological or behavioral, have been found.
How does the microchip work?
The implanted transponder itself is inactive and does not include a battery or other power supply. When a reading device or scanner is passed over the chip site, a radio signal from the scanner is picked up by a tiny antenna, energizing the transponder's electronic circuit. The transponder sends its unique number back to the scanner where it is displayed on a small screen.
The European Union (EU) has mandated that all horses be assigned a Universal Equine Life Number (UELN) consisting of fifteen characters. The first three numerals are a country code (for example, the code for the United States is 840, while the code for Canada is 124); the next three are a breed code; and the final nine designate an individual horse. In the United States, The Department of Agriculture and the American Horse Council are working together to develop recommendations on adopting a similar system for equine identification, and it is likely that compatible identification systems will be in place for many countries in the next few years.
Many questions related to dual registry, cross-bred horses, and horses of unknown breeding will need to be worked out as the systems are perfected and implemented. Note: microchips are designed to use a frequency of either 134.2 kHz (endorsed by the Equine Species Working Group) or 125 kHz (used by a major U.S. chip manufacturer). Some scanners read only one or the other; the newest scanners are able to detect both frequencies.
How can I get a permanent ID for my horse?
It makes sense to assemble several full-frame and close-up photographs as well as a detailed description for each horse you own. Record breed, color, size, markings, scars, cowlicks or whorls, and other significant features. Keep copies in your house and barn, and consider sending a copy to a friend or family member who lives in another state so that the information is preserved in the case of fire or another local disaster. If you decide to have your horse tattooed, branded, or microchipped, contact your veterinarian to work out the details.