A 4-year-old sexually intact male German shepherd with a 3-month history of chronic watery diarrhea was referred to the Veterinary Medical Teaching Hospital. Dehydration and serum biochemistry revealed hypoalbuminemia, and fecal material contained a large quantity of round arthroconidia that were microscopically observed. A specimen was submitted for fungal culture and yielded a white to cream-colored subsurface colony. Microorganisms derived from the colony exhibited chains of smooth, septate hyaline hyphae that were producing 1-celled arthroconidia. Geotrichum candidum was thus identified. Colonoscopic features included erythema, edema, and loss of the usual fine vascular pattern, with granularity of the mucosa of the descending column. Treatment consisted of oral administration of ketoconazole and metronidazole for 3 weeks, while oral prednisolone was tapered after 1 week of therapy. The dog’s feces gradually softened after the first treatment. Fecal smear examination revealed no trace of the yeast-like microbes 7 days after treatment was administered, and 2 weeks post-treatment the dog passed well-formed stools and had regained its normal body weight. The previously observed clinical signs did not reoccur, even after oral medication was withdrawn.

A 4-year-old sexually intact male German shepherd with a 3-month history of chronic watery diarrhea was referred to the Veterinary Medical Teaching Hospital. Dehydration and serum biochemistry revealed hypoalbuminemia, and fecal material contained a large quantity of round arthroconidia that were microscopically observed. A specimen was submitted for fungal culture and yielded a white to cream-colored subsurface colony. Microorganisms derived from the colony exhibited chains of smooth, septate hyaline hyphae that were producing 1-celled arthroconidia. Geotrichum candidum was thus identified. Colonoscopic features included erythema, edema, and loss of the usual fine vascular pattern, with granularity of the mucosa of the descending column. Treatment consisted of oral administration of ketoconazole and metronidazole for 3 weeks, while oral prednisolone was tapered after 1 week of therapy. The dog’s feces gradually softened after the first treatment. Fecal smear examination revealed no trace of the yeast-like microbes 7 days after treatment was administered, and 2 weeks post-treatment the dog passed well-formed stools and had regained its normal body weight. The previously observed clinical signs did not reoccur, even after oral medication was withdrawn.