Teach your puppy bite inhibition and stop your puppy biting.
When puppies are in the litter they will be getting constant feedback about how strong their bite is, and more importantly to control their bite pressure during play. When a puppy bites too hard the other puppy will yelp and the game will stop, sometimes for a few seconds other times much longer. Through the consequence of their behaviour (games stop) they learn to control their bite.
When these puppies leave their litter mates, new owners are told not to let their puppies mouth them, so this constant feedback stops.
Even though many dogs end up with very good control over their bite pressure, its more luck that judgment.
How to stop your puppy biting
We really need to be continuing where Mum, litter brother and sisters left off and keep that bite pressure information going, teaching the puppy/dog bite inhibition. What I am not saying is that you go around jamming your hand in your puppies mouth, but if during your interaction with your puppy he/she starts to mouth your hand, keep your hand still, do not try to pull it away, this is where most damage is caused by those needle sharp teeth, then if you feel that the pressure is a bit much shout “OUCH” loud enough to surprise the puppy into letting go, when he/she does, walk away with a grumpy attitude and don’t have anything to do with the puppy for 2-3 minutes. After that you can continue with your interaction.
Teach your puppy to take a treat gently
The other thing that you can do is to give your puppy treats using your fingers to hold the treat rather than having the treat in the palm of your hand, which is usually what happens when owner have had their fingers bitten a few times.
Hold the treat in your fingers, offer the treat to your puppy saying “gentle” if the puppy takes it without chomping your fingers give the treat. If on the other hand your puppy bites your fingers, again shout “OUCH” and withhold the treat, turn away from your puppy and leave it 10-15 seconds before tying again. Through repetition your puppy will learn that humans feel pain very easily and only if s/he is gentle with its mouth will it get the treat.
Try this at meal times, once the puppy’s food is prepared, hold a treat in your fingers as before, if he takes it nicely give him that and his meal, if not he must wait until he takes the treat carefully before getting his main meal.