I have a 7 mo. old puppy and at my first vet visit for immunizations, I wanted him micro-chipped. My vet said he would do it if I absolutely insisted, but that it is excrutiatingly painful and would prefer to do it when he was put under to be neutered. I did wait because I didn't want to cause him any pain if I knew I would have him neutered in a few months anyway. But I was wondering what everyone's experience was in having it done along with vaccines?