Two years after Congress directed the U.S. Department of Agriculture to develop regulations requiring that microchip scanners be capable of reading all types of pet microchips, the agency has determined that it does not have the power to mandate standardization of pet microchips or the scanners that read them.

The USDA maintains that its regulatory powers are limited: Because the Animal Welfare Act does not authorize the USDA’s Animal and Plant Health Inspection Service to regulate private pet ownership or the retail sale of pets, APHIS cannot mandate a single national standard for pet microchips or scanners.

Approximately 60 million dogs and 70 million cats are privately owned in the United States, according to the USDA. Of that number, 3 percent to 5 percent are electronically identified, the agency estimates. Of these, 98 percent are implanted with 125-kHz microchips. However, the 134.2-kHz microchip, implanted in pets in many other countries, has been endorsed by the International Standards Organization.

Efforts by the American Veterinary Medical Association (Schaumburg, Ill.), the American Animal Hospital Association (Lakewood, Colo.) and the American Society for the Prevention of Cruelty to Animals (New York) to encourage the U.S. animal microchip industry to adopt the ISO standard have met with little success.

The existing microchip infrastructure in the United States favors 125 kHz, since approximately 80 percent of the scanners used in this country can read only 125-kHz chips, the USDA noted. Because of that, and because of its existing limited regulatory authority, it would be difficult to implement federal regulations on pet microchipping, the agency said.

As a result of its investigation into the matter, however, the USDA plans to make microchips an acceptable form of identification for animals regulated under the Animal Welfare Act. Putting microchips on the same footing as other AWA-allowed forms of identification ideally will encourage their use, the agency said. [January 2008 PET AGE]