Pit Bulls are not supposed to have docked tails. If I remember correctly, if an APBT’s tail is docked they cannot be registered or papered (correct me if I am wrong on this). Some get their tails docked if an injury is sustained and it is medically necessary. I have also heard of APBT getting docked for reasons necessary to be a fighting dog but once again I am not sure of this.
Ultimately, there should not be any real health concerns related to the docking if it was done properly. However, your pit will not get to leave welts on your legs or knock glasses off your coffee table! 🙂