I have a silkie whos head just started to bob in a strange way. He seems to be fine otherwise but it's really bothering me. I just got him a few days ago and he appeared to be fine up until this morning. He was eating some grass and it looked like his was taking extra time to swallow the grass. His head would bob almost like it does when they swallow. It is happening every so often. He's eating and drinking. I treated him the other day for lice. I gave him a dust bath in Sevin powder. What is wrong with him?? His head just keeps bobbing!