Most pets have no problem with microchips, but when they do....the problems are severe! My boyfriend's little girl kitty, Mau Mau, has a chip and I have showed him this thread. He said she has had no problems with it, so he will leave it in. He has decided not to microchip his other cat, Buddy, though. I hope Halo has no further problems and the worst is over. Sending good thoughts and prayers Halo's way.