"To please your master is what the dog slaves live for," and his efforts and attitude do that.That the slave has at least all the emotional traits (and so responses) of a dog, so keeping your slave in the doggy role is the kindest thing you can do. This also includes a strong SM framework (not necessarily whipping the shit out of him - you punishing him when he has done bad, praising him, rewarding, making him feel good when he pleases Master)
A master essentially treats you as he would his real dog, (Mans best friend is his dog...dogs best friends is his Owner)
The tail however is also important for the pup's self identity, just as it is important have his doggy chain lock around his neck.
Not too tight, tight enough so that it cannot come off, loose enough so that it clanks (the padlock and doggy disk) against his dog bowl when he feels.
As a guide the correct tightness of the chain is when the Master can get his fist around the chain when he pulls on it (don't yank it) it would leave a gap of about an inch from Masters knuckles and the dogs neck.
When this is locked on the padlock is then just below the hollow of the neck.
Dogslaves are different to traditional slaves, some Masters can loose sight of that - or perhaps do not perceive the difference.
IMHO dogslaves are not that hard to satisfy (once you appreciated where they are coming from).
As with real dogs, they have strong loyalty, they will do there best for the Master, but if they get ignored, they can break from the pack and stray.