My teddy bear of a dog, Jake, actually let out a rumbling growl at the vet, when she was examining his infected ears. This is very very unusual for Jake, but he was obviously in pain. I'm sure that the fact that your dog was not treated well by humans, before you adopted him, makes the matter worse. The past abuse, as you know, makes him very fearful of things that other dogs would not think twice about. As stated by others, I'm sure the vets tools reminded him of past mis-treatment.

Despite an abusive past, this type of behavior is unexceptable. You should talk to an animal behaviorist.

In addition to this, you may want to borrow or buy a second hand stethascope. Just leave it on the floor for your dog to sniff and get used to (just make sure he doesn't eat it). When he gets used to it (days/weeks later), you may want to put it in your hands for him to sniff. Eventually, practice using it on him. Include lots of yummy treats and soothing talk. I would also suggest practicing exams on your dog. Play with his feet, look in his mouth and ears (once the pain is gone), press gently on his belly. The dog will get used to this sort of touch and begin to fear it less. He trusts you more than anyone, and if you do it, he will more likely let the vet do it.

My dog has some different behavior problems, due to a less than happy past. I was recently told by a dog trainer that my rescue dog, Addie, shows strong signs of being overly protective of me. Addie has never attempted to bite, snap, or even growl at anyone, even the vet. I would have never imagined her being less than the perfect baby I know her as. Through training we are working to relieve some of Addie's fears and anxiety (things that can lead to biting). In just a couple of weeks, I can already see her self esteem increasing.

Good luck with the new pupper, I'm sure he'll be a wonderful companion.