A 9-month old pet ferret was presented to a veterinarian with symptoms of weight loss, apathy, and hyporexia. Explorative laparotomy identified a firm mass of approximately 2 × 2 × 2 cm in size in the mesentery of the jejunum. Because of the poor general condition and the unfavorable prognosis, the ferret was euthanized during surgery. The mass was resected in total and submitted to histological examination which revealed a granulomatous and necrotizing lymphadenitis. Acid fast bacteria were detected by Fite-Faraco staining leading to the suspicion of an infection with Mycobacteria sp. PCR confirmed presence of DNA of members of the Mycobacterium tuberculosis complex, subsequently specified as M. bovis. The detected spoligotype SB2548 was described for the first time. Ferrets are presented to veterinarians with increasing frequency because of their growing popularity as pet animals. Since these animals are highly susceptible to mycobacterial infections, mycobacteriosis and especially zoonotic relevant tuberculosis should be considered as differential diagnosis.