While the romance didn't do ANYTHING for me (seriously, I thought Simon had more chemistry with Queenie the pig!!) but this story was quite entertaining in a totally different level. Namely, the "ANIMALS were the stars" level.
I thought the mayhem and mishaps that Simon was experiencing at the vet's office worth all the stars -- it brought HUGE smile on my face. I had FUN reading those moments. Simon also had a witty and sarcastic humor that worked for me (kinda reminded me of Emory from The Other Guy.)
However, like Gigi said, I definitely couldn't recommend this to anyone as M/M romance. You may get very disappointed. If you want to try, approach it as, uhm, "fun with animal" kind of story maybe :)