That is really interesting to read. I didn't know that and just assumed all dogs have the same swimming skills. I suppose like you mentioned, the ones with large heavy chests probably have a tough time as well as the dogs with long legs who awkwardly walk. Maybe those dogs just don't have good coordination either. My golden doodle has always been a pretty great swimmer. She loves water and could spend all day in there chasing sticks, digging for rocks and just cooling off. I know they make doggy life jackets. I wonder if there are some dogs who enjoy water, but just aren't good at swimming and if they would feel more comfortable in life jacket.