Naw, in my case there is nothing really causing physical harm as far as the punishment for pets goes.
Once upon a time, one of my fish was getting aggressive with some new fish I just added to my community aquarium. The usual passive fish suddenly got territorial and all bossy while his species "should not be" too aggressive. To avoid causing possible injury to other fish, I had to relocate him to a different tank for "reeducation". After a few hours alone in the smaller fish tank, I moved him back to the main aquarium. He became a lot less aggressive.
Well, my case is quite different since it's just a fish. As for smarter pets such as dogs and cats, they are just like little children. I do not believe in any physical punishment should be done to either pets or kids. There are always better ways to make them understand what is acceptable and what is not.
After a few hours alone in the smaller fish tank, I moved him back to the main aquarium. He became a lot less aggressive. 
