The Importance of Horsemanship

Socrates is talking to bullomarkus, where he starts talking about dogs and horses and horsemanship. Do horses that have been injured become better or worse with respect to the virtue of dogs or the respect that of horses? And polemark is says that can't be. So if you could teach somebody bad habits on purpose, surely that would be through bad horsemanship - but it's not clear that the teaching of horsemanship is the same as horsemanship.