As you said 'unbelievable!'
I was a bit perplexed that the owners seemed to let the vet continue to treat their dog despite his strange behaviour**?.
I must say on a general note that there are enough people addicted to human drugs but animal drugs is a new one even on cynical old me!
Lets hope he gets struck off and never practises again as it looks like this is not the first time. 
Em and Chad

Very strange how the owners did not rush thier dog out the door right away .  I know a lot of people are in awe with their vets but if my vet pulled a stapler out then I would be asking what the H*** he thought he was going to do with that  Nora

The man couldn't spell 'Pip' for crying out loud!  I'd have rugby tackled him if he went anywhere near my girl wielding a stapler.