I have a two and a half year old jack russell. For the past few months he keeps vomiting. Not a lot, just usually once or twice a week. It seems to happen at random, it's not after just eating or anythihng that I can figure out. He isn't sick at all - he is his usual hyper, energetic bouncy self. At first I thought it was because he was eating things he wasn't supposed to - it seemed to start when I would catch him eating the ashes and coals in the fireplace or eating the fake grass in my plastic potted tree, but he hasn't done any of that in a long long time, but the random vomiting continues. Could this be the result of worms or something like that?