If you think you’re eating meat when you have a hot dog, I’m sorry to tell you that you’ve been getting played. We all have. What’s actually in them, then? “They’re just tubes of fat,” Tyler Rouse, a pathologist at the Stratford General Hospital in Ontario, Canada, explained to Scientific American. Rouse got curious as to what exactly where in dogless hot dogs a couple years ago and realized that he had the ability to figure it out.