Is there a registry one might consider more used than others?

Good story, Charlie. Talk about making that investigation easy.

I'll have to see something very solid about cancer to stop chipping. Even then if the risk is small enough I may even continue to chip because in my mind I know of no greater tool to protect my dogs. Tattoos/brands can be faked and altered but it takes a very determined thief to go poking around inside of a dog to remove a chip.

The most common in the USA is Home again, avid and CAR. I personally like CAR because the chips are smaller, don't tend to wander, which means better/easier delivery on smaller dogs/puppies and they don't charge for information updates. Boxes of chips from them are also very reasonable and you can do it yourself if you're comfortable giving shots.

I will always do chipping. A friend of mine had her boxer stolen and resold twice in the same incident. She found her dog outside of a supermarket in a car over a year after being stolen and the only way the police believed her was because the dog was chipped. After all one boxer/lab/gsd can look an aweful lot like another.

Anyway long story short she was able to find out from the very angry people who were sold a stolen dog who stole her dog which turned out was a family friend and bring that person up on charges.

Thanks Melissa.

It helps to hear people's opinions AND why they lean that way.