If your ferret occasionally has a few stools with a liquid or loosely formed consistency and has no other symptoms, it may be normal. If, however, the diarrhea is persistent (lasts more than a day), recurrent (returns frequently) or other symptoms occur, medical attention is needed.
Continued diarrhea can cause a loss of fluid and electrolytes, leading to dehydration. Diarrhea occurs when the intestinal tract fails to absorb sufficient liquid or increases the amount of liquid secreted into the feces, or both. Diarrhea is a symptom and has many causes. Diarrhea is one of the most common manifestations of intestinal tract disease in ferrets.
For more information, please read
Diarrhea in Ferrets.