My dog had an Avid chip that migrated into his shoulder. We found it after he got a ResQ chip at our shelter. My other dogs alsp have a ResQ Chip because it is what our shelter and animal control uses. I wanted to make sure that they would be able to easily read the chips if any of them fell into their hands. Most of our vets have universal readers. The one who found the Avid chip also found the ResQ chip. Unless you are moving or going overseas, I would call your local animal control and find out what chip they put into the shelter dogs that are adopted and go with that one. What ever chip you get, make sure it is registered with an international registry as well as the company you got if from.