What is wrong if your rabbit has diarrhea?

Rabbits often have a pungent grape-like cluster of soft stool called a cecotrope, this is not diarrhea and is in fact reingested (aka eaten) by the rabbit to retain essential nutrients. These cecotropes should be left in the cage for at least a short period of time so they can be reingested. However, cesotropes can become overly soft and runny and can be the result of not eating enough crude fiber or a diet too high in indigestible carbohydrates.

If, however, it is diarrhea and persists for more than a day you should take your pet to a veterinarian immediately as this could be any number of potentially fatal conditions.