Hi! I have a 6yr old 5lb Yorkie and I have run into this same problem ALOT over the years. There most likely isn't anything to worry about. It's probably stomach acid. My vet has suggested 2 feedings daily. I now feed Ace at 6am and 6pm and that has helped SO much. I feed him Cesar, half a container each time. He also has access to hard kibble all day (but rarely will he eat it). Other great things for their digestive track are plain non-fat (unflavored) yogurt, if your dog won't eat it you can give it to them via a medicine dropper. I've also used white rice and tukey breast. Anything bland. I hope this helps! It saved me from all of that clean up! A comforter can only be washed so many times :-)
