tail docking

Question
When I take my puppies to the vet to have their tails docked how much length does he need to leave ?

Answer
Well, you don't HAVE to dock their tails at all.  So first I'd ask why you're doing this?  I suggest you do some research on how painful this is and the reasons for doing it.  Just do a keyword search on "Docking a dog's tail" and then decide.
Delores