
No a microchip alone isn't proof of ownership, just like KC registration in your name isn't. You need to build up a variety of proofs should you ever need to prove a dog is yours -it all adds up. So microchip and KC registration in you name, registration at your vet, photos of the dog in your home, etc. Should there ever be a dispute ownership will go to the person with the most proof -UNLESS there is a sales receipt available.
I certainly would NOT want microchip to be proof of ownership. How easy then to steal a dog and just chip it in your name!!