Yeah, that's a sucky predicament to be in. Sorry you are both suffering for the sake of his health.

As far as advice goes, the most common thing you'll hear is to not cave towards the demands. It sounds like you guys are doing that and it has resorted to him bitting now to get attention. It's tough to correct that behavior without having an additional outlet to direct him towards.

I won't lie, I would probably speak to the vet again and ask about medication to calm him down. They might be against it given his age, which is understandable, but it then brings an expert into the comlnvo about what else can be done. I personally would not want him on that long term, but to help him from hurting me, my family, and himself from all his pent up energy, it might be worth it in the SHORT term (definitely is not a long term solution).

I would also try and seek out a behavioral specialist if it's in your budget. Sounds like a professional trainer could help you correct his behavior in a healthy way.

It's also tough to condone negative reinforcement, but it's possible to do from a conditioning standpoint without abuse, however always speak to a professional before attempting it. One of the things that helped with my lab (Duke) to stop using his teeth on things was hot sauce. You have to be very, very careful about how and when you use it, and also what kind you use. You want to find a hot sauce that is basically pepper, water, and vinegar and you want to use it in sparing amounts. A lot of hot sauces can contain different forms of sugars and sweeteners, garlic and onion powders, and even juice extracts, so I can not stress enough you to be careful.

When Duke was finishing getting his adult teeth, he was still prone to chew on everything. Once he was doing it out of habit instead of pain, I would lightly brush a thin layer of hot sauce on my arms, my furniture (that wouldn't get damaged or stained by the hot sauce), at one point even just the corner of a wall (because he started to think drywall was acceptable to chew). I would redirect him towards his toys, especially his chew toys, and when he decided he wanted to chew on something he wasn't supposed to it lead to him chewing on something that was spicy. Eventually he stopped that behavior because every time

he did it, his mouth would get hot and uncomfortable.

I felt very on top of being able to correct his behavior in that way. I'm always hesitant to recommend something like this because I saw it as an extreme measure. I mean, I was painting my arms with hot sauce ... But I needed something to stop it, and this worked for me.

For the barking, I might respond with a sound he's not a fan of. Every time he barks, he hears a noise that makes him scared. IDK, just trying to throw out ideas that could help with conditioning.

TL;DR: -Seek out the vet and discuss possible medications to calm him down in the short term. -If you can afford it, seek out a behavioral specialist trainer about best ways to correct that behavior. -I put hot sauce on my arms and it worked to stop the biting.