Hi Fireman29-
That was awesome of your friend to take in the pregnant puppy!
Have you had a recent fecal test done? If not, I would recommend taking in a stool sample and having it checked for all types of worms and parasites, including Giardia and Coccidia. They are common in puppies and can cause intermittent soft stools and diarrhea.
The supplement called Perfect Form by The Honest Kitchen was very helpful when we were going through this with our puppies. But, no supplement will fix it if they have worms or parasites.
Here is a link that may be helpful: http://www.dogaware.com/health/digestive.html
Good luck!
