We have a 1 year and 1 month year old F1 labradoodle (half chocolate lab, half standard poodle). We got him when he was 3.5 months old and he is now about 50 pounds.
Recently (within the last month) he has started chewing on the baseboard corners (2 in particular) and one windowsill. We were able to correct the windowsill chewing by moving "his" chair away from the window, so he can't reach the wood to chew on it. However, nothing has worked with the baseboards. We have tried the following with no results: bitter spray; hot sauce; rebuilt the corners with wood filler so maybe he would forget he ever chewed on them (worked on another corner he chewed a little, but did not work on the 2 corners he loves); and purchased plastic corner protectors (chewed them off). The only thing that has worked is blocking off these corners, but this requires the use of two barstools, a tall cylinder fan, a chair, and a vacuum (the two corners are on the sides of a small desk area - kind of an open cubby underneath so have to block off the entire opening), so we would like to find a more permanent solution rather than using all of our household items to stop him.
We are out of the house from 8:15 to 6:00 (sometimes earlier), not including when I come home for lunch. He is crate trained but we quit using the crate about 5 months ago - we started off with just letting him out of the crate in the afternoons when he was home, and then moved to all day. He went 3-4 months without destroying anything before this behavior began. He goes to doggie daycare twice a week, and the other 3 days I come home for about 40 minutes at lunch to let him out/play. We usually go on a 30-40 minute walk each night, and 20-30 minutes in the morning (more often on the days he will be at home rather than daycare). If we go to dinner during the week, we only go to dog friendly places. He is treated similarly on weekends - typically only go to dog friendly restaurants and go to the dog park or on a hike on both Saturday and Sunday.
I realize a longer morning walk could help, but he is actually quite lazy and tends to sleep in and only get up/go on a walk when I force him to. Also, this behavior started prior to the morning walks and the 20-30 minute ones we go on now have shown no change. He has PLENTY of toys - antlers, Benebones, Himalayan tree root (that resembles a block of wood), countless stuffed toys with squeakers, Kong, tennis balls, etc. We also leave the TV on but that was more to prevent him from barking.
I do not think it is separation anxiety, as he does not bark or whine when we leave and we receive no noise complaints from the condo community we live in. And, there are multiple other wood sources he could destroy but has really devoted himself to these two corners. He only does this when we are not home so it is impossible to correct his behavior when he is doing it. Other than the chewing, he is very well trained and a great dog.
Any tips? We've considered bumping up daycare from 2 to 3 times a week, but it is pretty pricey and I am not sure it would help.