I’ve been playing this game for awhile now, and I’ve just figured it out. When you get to level 34 you have to collect all five of the dogs. You don’t merge any of these dogs until you get all five or at least it should merge on its own. I don’t really know, though because I haven’t gotten all five dogs; I only have four of the five. After that the developer gives you duplicates that you can merge to get the remainder of the dogs that you don’t have. Yet the problem is that you end up merging the duplicates to dogs that you already have. I guess you have to keep trying or until you get bored and go on to another game; which is happening to me. I’ve found a few that are more interesting than this one. So there’s a big possibility I’ll uninstall, if the game doesn’t improve.