12 Year old english setter begins to go in and out obsessively after dark. This will go on for hours...

Any type of behavior that is sudden, new and strange should really be discussed with your vet.

In the mean time, how about putting him in a crate?

Many older dogs suffer from cognitive dysfunction. Talk to your vet.

My Dog a Westie (male) 10 months old continually barks at and with the next door neighbours dogs and just will not stop. His temperament is good but whens he hears the dogs just over our wall he starts barking. I would appreciate any help? Thank you.