Manthika

Basic isekai shoujo formula +a cute dragon with the negative side of an ugly ML, though I'm sure there probably exist people who won't think the love interest prince is ugly.  I think he's terribly drawn, but oh well.  It's nothing special, but if you love adorable dragons you can't really go wrong picking this one up sheerly for baby dragon content and the poor dog trainer winging it (pun intended) with said dragon's training.