I have a three year old chihuahua who seems to occasionally suffer from upset stomaches. Every now and again, he'll eat grass outside, then come in and just lay around on the floor somewhere (rather than play with a toy or curl up on a couch and sleep). When this happens, it'll take a few hours but usually by night he'll start eating again. He had one such episode yesterday for a brief period. After he started acting normal, he still would not eat. So yesterday, he didn't eat anything (save bits of grass every now and again) and thus far has not eaten today. He acts almost perfectly fine, except for his growling stomach and dismissing any food offered to him. I have not yet taken him to a vet to find out about this. Also, and I hate confessing this, but he never had his shots as a pup (something I'm planning on taking care of in a week). If anyone can offer any thoughts or ideas on what might be going on, I would greatly appreciate it. Thanks in advance.