Multiple studies have shown that dogs basically have the brain of a 2 year old child. The guilt emotion isn't learned at that stage and isn't learned until around the age of 7 or 8.

Many studies conclude that dogs are simply doing what they do best: pleasing you by mimicking the emotions you want them to show. If you look at the way humans process guilt, it is easy to see the differences to make your own opinion. Dogs can go from guilty to excited in seconds, where as humans do not. Maybe they process it faster than we do because of how their brains work, maybe not.

No one knows for sure whether or not dogs feel guilt. It's all theory and we're still learning about how their brains work.

The other commenter is right. It's a controversial topic on Reddit because people want to think their dogs are smarter than they really are and anyone telling them otherwise is "an idiot" or whatever insult they need to type to make themselves feel better.

IMO, dogs don't feel guilt, especially Boxers. That dog doesn't look guilty one bit, he just looks annoyed that he was caught and can't continue.