Hi there! I am a fellow chihuahua owner. I have a few friends who have chihuahuas too and they can be a little difficult to train because most chihuahua owners spoil thieir little ones and let them get away with a lot. Personally, I have not taken Guapo, my chihuahua, to obedience because he has been quite easy to train but all my friends have done obedience with their chihuahuas and it has worked quite well!! Good luck! I hope to see some pictures of your dog!