Older Dog Bitting!

[jduch1961]

My sister has a 12 year old Husky/Border Collie mix that has been a very good guard dog! He has had a tendency to be aggressive toward strangers or rodents that venture onto their country property. He has never ever been aggressive toward my sister and her husband.
Last week he snapped at my sister and actually bit my brother in law. My sister is very upset over this and will be bringing her dog to the vet tomorrow to see if he has any health issues that would cause him to do this! If he doesn't they have to consider putting their beautiful boy down!
They are beside themselves over this of course and so am I. I'd just like to know what type of things the vet should be looking at. Since this is a new vet to them (they've only seen him once before) I want to make sure that since he doesn't have a personal connection to this dog that he covers all aspects health wise that could cause this type of behaviour.
Any help would be appreciated.
Jackie

[clarence]

This dog needs some obedience training.

Save the cost of putting the dog down, and take bring the dog in for a course.

Why did the dog bite on the one occassion, I don't know, wasn't there. THERE ARE A MILLION POSSIBILITIES, including one of them was trying to take away his bone.

Chances are though, that your brother in law misread the dog's aggressive behaviour and didn't back away when he should have.

NOT THAT THAT IS AN EXCUSE. This dog must quickly learn its place in the family hierarchy so that if he should exhibit an aggressive tendency to someone he knows, a simple command will bring his aggression down.

12 years old is not to late to train a dog...but it is good that the dog is being brought to the vet just in case the problem is medical instead of behavioural.

Clarence