All my Yorkies have vomited regularly. I've had three that have passed away and they all lived to 14years, the one I have now is coming up to 16years and he's been the same. Watch when you walk your baby, they tend to grab pieces of grass and chew on them, they do this to induce vomiting to clean out their stomachs. I've found they are very sensitive to foods, cleaning products and indoor air pollution. Unless it's happening daily and forcefully I don't think you need to worry too much. Just keep an eye out for when it's occuring and see if you can match it to a particular occurence, certain food, after walking, after cleaning etc.
