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There are a great many things that can cause diarrhea in puppies, and I would encourage you to have a veterinarian examine her and check a fecal for parasites. Besides worms and protozoal parasites, there are bacterial and viral infections that can cause diarrhea, and some of these (such as parvo) can become life-threatening.
In the meantime, I would suggest feeding her a mixture of boiled white rice and chicken or lean ground beef. Do not add any butter, salt, or spices. This is a bland diet that can be fed for a few days that is very easy to digest. I would not recommend giving her any over-the-counter human medications for diarrhea as you can sometimes cause more damage with these medications, and it would be important to find out what is causing the diarrhea in order to properly treat it.Good luck, I hope she feels better soon.