I have a 9 month old yorkie that I have owned for 7 months now. Last Tuesday afternoon he threw up, then the next morning he did also. At first we thought it was because we just had switched his food, so we went back to the original. For the next couple days he was fine, but then on Saturday he threw up 3 times all yellow bile. He hadn't eaten all day. We went out and got wet food to mix with his dry, and this seemed to help again for a couple days. Then last night he was very tired and went to bed very early. Any ideas would be really appreciated. I am a very worried parent!