Awwww. I feel terrible for you, worrying about your pup so. Dogs are adaptable, resilient creatures and the pain meds they may have him on, will help him sleep thru the stress of being at the doctor's office. Did you try the "Search" function at the top of the page here at EBN? Just typing in "urethra" OR "prolapsed" should get you some older posts about it. Someone will come along with experience on this!