During the last year, he developed an odd problem where his jaw would hang open, his head tilted to the side, and he would fall over regularly. He also became unable to negotiate stairs. He was diagnosed, after much expense, with "bilateral trigeminal neuropathy." Some steroid treatment may have helped, but by and large it was idiopathic.

During this time we noticed a change in behavior. He became very nervous at times, likely because of his balance. While before this I was able to pull his front legs out from under him if he disobeyed a "down" command (as I was taught), he would now actually nip/bite at me. I only did this once, in the car, on the way home from the vet. Some recent events were that he bit my sister in law's foot as she was playing and teasing with his food. We chalked that one up to her behavior, not his, but it bothered us anyway.

Last week he began vomiting on a daily basis. I took him to the vet and x-rays showed a foreign object in his stomach. He was in for surgery and the object, a plastic toy (no idea where he got it) was removed. Tonight, we were being very careful with him knowing he is in pain and nervous. I sat down next to him and tried to get him to lay down. Being careful, I lightly tapped him on the foot and said "down." I did this again. On the third time, he clamped down on my hand, not a full bite, but hard enough to break the skin and bruise. It was more of a warning, but my wife is freaked. She's concerned that this behavior may come to light when we have visitors, especially children.

I've also noticed that he is more stubborn, disobeying "come" or "drop" commands at times. And in the few times we've gotten into a confrontation, it became clear that he would not back down no matter what.

We love this dog very much, as our vet bills for over $3000 this year will show. He is smart, kind, and lovable. But... he has an aggression/discipline problem. We discussed this tonight, and I think our 3 options are: 1) ignore, and be careful not to instigate. 2) try to train him out of it, perhaps with professional help, and 3) give him up or have him put down, and if this bite were reported, they would require this. We're not comfortable with 1) or 3), so I guess I'm looking for help with 2), as well as some feedback on this problem. Again, this is a dog that gets perfect treatment, has never been abused, and we have done everything right as far as I know. Thanks for any feedback you can provide.

A: Have his hips, spine and elbows x-rayed. It may be painful for him to go into a Down position, also to get back up from lying down. These problems are common in large breeds. Before proceeding with training, you need to know about this. If it is pain, on top of his other problems, then you'll have to decide whether pain medications for the orthopedic problem are enough, whether you want to go with hip surgery -- you can see the potential complications.

There are some terrific training methods out there, non-confrontational, that could help you a lot with this guy. But I can't see ever trusting him around small children. That neurological problem is serious stuff. We can't ever know just how difficult life may be for him. Some conversations with your vet can help you decide about that. It sounds as if the dog is not completely in control of himself, and if he can't control himself, then of course there is no way he can reliably obey commands.

Start with the vet, and give yourself a little time to make a decision. I'm so sorry for what you are going through.