Gastrointestinal (GI) disease is common in pet ferrets. According to Delaney, unique ferret anatomy and physiology, including rapid GI transit time, and short, simple GI tract predisposes to GI disease [1]. Etiologies include bacteria, including helicobacter infections, virus, parasites, inflammatory conditions, neoplasia, foreign body-related diseases, and stress. Some practitioners report improvement in some refractory cases with diet modification, which suggests dietary allergen or intolerance. A thorough workup is critical for distinction between etiologies typically producing similar clinical signs and symptoms [1,2]. Diarrhea is one of the most common presenting complaints, and can represent a myriad of underlying and multifactorial causes (Fig. 1). Table 1 includes common and uncommon causes of diarrhea in pet ferrets. History can be helpful in determining underlying cause. Ferrets under 1 year of age are more prone to foreign body ingestion, coccida and proliferative colitis, while coronavirus and Helicobacter mustelae typically affect older ferrets [1,2]. Diarrhea occurring soon after introduction of a new ferret into the household suggests an infectious etiology, such as coronavirus, coccidia, or possibly giardia. Infectious agents such as Lawsonia and Mycobacteria, however, tend to affect only a few members of a group [1,2].