where do people hear such rubbish, i too have been asked if my dog has a lock jaw , its the most ridiculous thing you keep hearing, will some one be honest and say they thought it was true and say where they get their information.
its stubbornness tenacity and instinct that makes a dog hold on and not let go.
some people use a stick as a lever to open the mouth of a dog when its not letting go of whatever its holding and wont listen to a comand but that doesnt mean its locked it is just too strong to open with your hands and maybe you wouldnt want to put your hands near the mouth of a prey e