This just recently started. He's still going in his litter box, nothing about his bowel movements has changed. He's neutered and almost 2 years old. We took him in as a stray when he was a kitten so we haven't clue when it comes to breed, but he is a long hair. It tends to happen if he takes off running or jumps if something scares him. Sometimes he just sits down and when he gets up and walks away there's just a little ball of poop left there. It's not just getting stuck on him a falling off, it's always a pretty decent size ball of poop. It's the consistency of normal poop too. We did just change his food from Friskees to Purina, everything else is the same. Any ideas as to why he's just losing his poop?