So I have four 3 week old puppies who have all seemed to be doing fine. Up until yesterday evening when I came home I noticed some very soft stool that looked like diarrhea. And then again early this morning I saw more. Is this "diarrhea" caused by over eating, parasites, etc...? 3 out of my 4 puppies are very playful now, while one of them is alot more sleepy. He will play, but just not as much. He is less active. I think he is the one with the soft stools. He seems sleepy all the time but as soon as he sees mama, he is the first one to rush towards her and eat, and is always the last one to finish eating. So he is eating very well.