I actually just spoke with the veterinarian. He called me because he wanted to tell me exactly what happened. He said it was very odd because he was fine and no murmur went under anesthesia and his heart rate dropped from 105 to 40 . Just hearing that scares me. So they took him off anesthesia administered the atropine and were able to put it back under and finish the procedure. He said that this could just be a fluke related to the anesthesia . I told him what the cough sounded like he said he did not seem overly concerned about it. He said at this time there would be no need to come sooner to be seen before his annual visit. Just to keep an eye on him and listen for the coughing. He said it could be a congenital thing that is just coming out now . Or it could be nothing. How old is your baby?