Go to the dogs 大不如前，衰落
The employee can’t get paid and this company is going to the dogs.
Dog days 酷暑
I love to be in the swimming pool during the dog days of summer with friends.
Every dog has his day. 人人都有走运时
You may become famous someday. Every dog has his day.
Let sleeping dogs lie.
Jill: Should I ask the boss if he's upset at my coming in late in the mornings?
Jane: If he hasn't said anything about it, just let sleeping dogs lie.
You can't teach an old dog new tricks.
Good luck getting Grandpa to start going to yoga with you. You can't teach an old dog new tricks.