make sure they do preliminary bloodwork and blood panels, if they say it's not necessary please request it anyway, it's only around $50 extra. make sure they use gas to administer the anesthesia, no injections! and ask if they're familiar with working with very small dogs just in case. that's about all really, it's a simple surgery, the anesthesia is the only thing i've ever heard of doing harm, but you can avoid that by checking for those first 2 things listed above. let us know how rocky does after his surgery