That sudden shift in your golden’s behavior sounds really tough, especially since you haven’t changed much around him. Sometimes, even subtle things we don’t notice - like a new sound outside at night or a small injury - can set off anxiety. It might be worth a quick vet check just to rule out anything physical, especially since the barking is nonstop and focused in the evenings. Also, I had a dog who started barking more at shadows and noises when the daylight faded - turns out he was a bit more sensitive to the quiet and darkness. Adding a soft night light and some calming music helped ease his nerves. Maybe something like that could help your guy feel less on edge when it gets dark? Keep an eye on any patterns or triggers, and if the vet gives the all-clear, sometimes a short consultation with a trainer or behaviorist can help pinpoint what’s bugging him emotionally. Hang in there - it’s hard when our calm buddies suddenly