Because they can't speak out and tell you their problems, you need to observe their behavior and performance. You and your dog share the same risks that stress presents. Some dogs handle all this with aplomb. Others react with varying symptoms, often failing to respond handler's wishes. Many a handler has come out of the ring cursing the handful they had to contend with that go-around.
Most animals are happiest when they have a set routine.
They get let out of their runs at certain time, they get fed at a set time, and in the same place. Kennel or home surroundings are constant. They gain confidence by this routine. They know what and when to expect things to happen. In effect, they are in control.