A dog puts his ruff up when he is SCARED. That is the first sign of Defense Drive kicking in and the dog is defending HIMSELF. Every time a dog puts up his hackles in a situation like this he is being DEFENSIVE. The hackles up is to make him look bigger and tougher when he is really afraid.
A dog in defense will bite. No doubt about it. A dog in deep defense may also exhibit fight drive and then you have trouble if he bites because he is not about to back down.
What can you do? Be careful. When his hackles raise, redirect him and get him thinking about something else (do NOT comfort him or reward him as that will simply convince him there IS something to be afraid of).
When the vet comes muzzle him. Period. Or when you go to the vet. You cannot risk the vet's hands. You may need that vet to do surgery someday.
A dog in defense will bite. No doubt about it. A dog in deep defense may also exhibit fight drive and then you have trouble if he bites because he is not about to back down.
What can you do? Be careful. When his hackles raise, redirect him and get him thinking about something else (do NOT comfort him or reward him as that will simply convince him there IS something to be afraid of).
When the vet comes muzzle him. Period. Or when you go to the vet. You cannot risk the vet's hands. You may need that vet to do surgery someday.