Microchipping your dog
In a few words a dog microchip is the size of a grain of rice inserted under the
dog’s skin. If you are feeling sorry for your pet consider it being like a rabies
shot. It will sting a little but it is for its own safety. It is your pets permanent
id tag. It will not fall off no matter what.
When a vet, or a kennel, or the pound encounters a dog they routinely "scan" the
dog with a handheld device that can pick up the id from the chip and give them the
info then need to contact you. Scanning is completely painless. They don't even
really have to touch the dog, just wave a wand near your pet's back or belly.
Then they will call you to come pick up your pooch.
For more info:
Here are some stories of pets reunited with their owners because of microchipping
After 5 years and 850 miles
After 7 years
Never give up.