A 9 month old pup has a broken tail, is unsure when and how it happened.  Breeder noticed it when the dog was at their place. (breeder now has dog back).
Now looking for new home for it.  In which I am considering. 
I am wondering if anyone knows if the tail can be fixed? and also be no traces of the broken tail eg bumps in the tail.  once it is fixed.

Well any broken bone will leave bumps so it wont be entirely bump free and nto sure why that needs to be a consideration. However, with regards to fixing it it depends on how severe the break is. If the nerves have been damaged then they may take the tail off.

Jesse

Think you mean that a dog was returned to it's breeder and the breeder noticed that the dogs tail was broken. If the tail has been broken for some time then amputation may be required, healing tail damage is very difficult anyway, if it is near the end it may be worth trying to get it to heal but if not it may be kinder to have the damaged part removed.

The usual cause of a pup getting a damaged tail is getting it shut in a door but they can do it by wagging hard against a hard surface.

No the breeder got the dog back after the broken tail was noticed. 

That does not alter what I have said. Wherever the tail was broken it is broken and requires attention now.

Broken tails can sometimes be splinted and healed if they are treated immediately after damage.

Others can go gangrenous (as I know to my cost) and require amputation.

Depends really on how bad the damage is and when it happened.

Hope the pup is OK.