Ok well my thought on this is that why would you put your dogs through all of the trouble and pain of getting tatted for the purpose of identifying them if stollen. If in fact they are, god forbid, rarely do people get there pets returned to them.
Lost sure, possibly but stollen probably not!
My family breed rabbits and several breeds of dogs when I was a kid. We had our animals including the dogs tatted with our initials using an ear punch tatto kit like the one below.
If you wanted to do it you may consider this type on tatto.
Rabbit Tattoo Equipment, Rabbit Tattoo Kits , Rabbit Tattoo Supplies, Grand Champion Tattoo Kit, Rabbi-Tatt Battery Operated Tattoo Pen - Rabbit Cages, Rabbit Hutches