A crup is basically a Russel terrier but it has a forked tail. How would Ron know Russel Terriers exist? It is more likely that he would have the wizard equivelant of this as his patronus: a crup. The crup suits Ron’s character: it is a scavenger and will eat many varieties off strange things. They are probably wizard made as they love wizards and hate muggles. What do you all think?
Another thing. In Order of the Pheonix when Trelawney and Hagrid are both put on probation it is said that Uxbridge sits through all lessons with both of these teachers. How is this possible? She has her own lessons to teach and Hagrid and Trelawney must have some overlapping lessons. The only possible way I can think of (other than plot hole) is a time-turner… this idea seems a bit strange to me though.