The reason why dogs always wake up in the middle of the night to poop may be because they did not defecate at night or ate too much before going to bed. It may also be because of a bad gastrointestinal condition, so they have developed the habit of waking up in the middle of the night to poop. The owner can take the dog out at night after the dog has eaten, and then do not let the dog eat. If the dog has a bad gastrointestinal condition, he can feed some probiotics regularly to help the dog regulate his gastrointestinal condition.