Re: training your dog to be quiet, I agree. But if you don't know how to train your dog, then hire someone else (or a professional) who knows how to do it instead.
Re: possible medical issues, it's totally possible and this should be the most realistic thing to do, before even considering "putting your dog down" for barking all the time.
Best advice you can get is here in quote, OPRe: possible medical issues, it's totally possible and this should be the most realistic thing to do, before even considering "putting your dog down" for barking all the time.
I believe any dog can be trained, no matter what age it is - its just a matter of time and effort
If you haven't trained your dog at this point I assume you have 0 knowledge in this area so you should really find a person who know how to do it