Rolex …….lots of good advice in the preceding threads. Problem is sometimes with relentless nipping and the 'personality' of the offending pup then it goes without saying that there is underlying innate need to bite — prey drive— that requires it to be inducively channeled to offer any relief. Read 'off-switch'. The pup needs be 'used-up' in blunt terms IMHO.
A flirt pole with a bite accommodating stimulus of fabric/rope/linen-bite-roll offers an inducive means for a mouthy bite-frenzied pup to 'spend' its prey drive. Five to ten +- minutes of play engagement offers a controlled outlet to satiate prey drive. Satiation literally is the operative word. Duration will be governed by the innate genetic degree of drive. Ranging from none to high. Dobermans per-se fall within the spectrum of mid to high by Doberman default. One fact holds certain — at some point drive will diminish and ultimately be extinguished for the time being. Recovery of drive might be hours or into tomorrow when the cycle repeats all over again.
Incorporate the play, chase , bite, tug and culminating in victory tug win into basic OB of sit, stay, down, here/recall. Detach the bite lure from the flirt pole line as becomes a stimulus trigger in continuation of inciting drive. Use food to lure/INDUCE the posture being sought. +Reinforce the compliant response with the luring food reward. Non compliance is -Negative Punished by withholding food reward until compliance occurs. No more and no less during this vitally important formative period of learning. To add another level of intensity/enthusiasm for compliant behaviour then incorporate tug as reward/+positive reinforcement using the fore-mentioned bite-toy drive inciting stimuli. A long line and smooth collar are required to direct and contain the pup when allowing a victory lap with tug toy clenched in mouth.
A short duration regimen as outlined above multi times daily instructs the pup what it is permitted to sink its teeth into a what it cannot — thus alleviating ankle and hand biting that in essence is remotely prey and motion inspired.
OR visit Elizabeth Barrett's DT thread and test those waters.
HERE
Refrain from measure 5 — similar to what you described doing with no resolve — in the linked video lest hand shyness and defensive awareness of unpredictable hand movement will evolve. Read:- handler directed aggression if heavy handed leash correction is errantly and unfairly used.
In the common bond of Dobermans…….Mikel