How do you know a hamster has diarrhea?

A hamster has diarrhea when its stool is unformed, soft, and watery. Usually there is also a strong smell, frequent passage, abnormal color, lethargy, poor appetite, and a wet rear. Diarrhea may come from indigestion, bacteria, fungus, or virus.

If mild, give probiotics; if no improvement, add smectite and bentonite. Normally avoid too many watery fruits and vegetables that burden the gut.