They also do not indicate a preference for one method over another or one manufacturer or registry over others. The chip, about the size of a grain of rice, is inserted between the shoulder blades with a syringe-like instrument. It contains not batteries or chemicals and has an active life of about 25 years. The age at which this can be done varies with the size and development of the dog, as a certain amount of muscle tissue is necessary. With larger breeds, it can be done by 7 weeks, which is when most puppies go to their new homes.
Most vets now have the capacity to insert chips.
The chip, when scanned, will reveal a code that is unique to the dog. There are currently 5 companies selling microchips for animals and selling scanners. Each scanner will, of course, read that company's chips, and some state that their scanners will also read the chips of other manufacturers. Companion Animal Retrieval System using a microchip which makes use of the Destron chip and scanner. Most companies will donate scanners to local shelters and pounds if they can get the vets in an area to buy their chips.