Digital Angel, the world’s largest manufacturer of implantable microchips for animals, is proposing that biothermal RFID chips be used on a sampling of the world’s 25 billion chickens as an early warning system for avian flu.

Avian flu is currently only identifiable via visual means, such as discoloration of the beak, sneezing, diarrhea, or sudden death. However, using a biothermal chip and an RFID reader poultry farmers would be alerted to elevated temperatures in the flock, company executives say.

According to Kevin McGrath, president of Digital Angel, while a temperature spike in a single chicken may not be caused by avian flu, if a representative sampling of tagged birds had a temperature spike, it might be an indication of trouble.

"If you end up finding 20 to 30 sentinel birds with higher-than-normal temperature, that is an indicator that you may have an infection. If you wait till the bird population is dying, it is too late," McGrath said.

McGrath proposes tagging every 250th bird in a flock.

Digital Angel is in talks with health ministries in Asia that have expressed an interest in biothermal chips.

The biothermal chips are approximately 10 millimeters in length and are inserted in a bird’s breast with a single inoculation. About 3 million dogs and cats each year are currently tagged with a Digital Angel RFID chip.

The company also designs tags for humans, under the name VeraChips, which are used primarily in medical applications and some for security.

McGrath also said the U.S. military has received a proposal for biothermal chips to replace dog tags on soldiers. Along with the chip, if each soldier also had a GPS scanner on his or her belt, a commander would know the location and relative health of every soldier in the field.