My little man is chipped. The day he got it, it did bother him after the anesthesia wore off. I had the chip put in at the same time as his neuter. I'm glad I did it this way; I'm sure it would have been more uncomfortable without he anesthesia. His back was bloody where the vet inserted the needle. I don't know why it was so bloody. It could have been normal, or the vet did a poor job of inserting it. Fast forward to today, over a year later, the chip doesn't bother my pup at all. He doesn't even know it's there.
