[Inappropriate lactation syndrome in a Holstein heifer].

The present case describes an unusual lactation of a 15-month-old,unbred Holstein-Friesian heifer, which had four swollen, ampouleshaped udder quarters with milk secretion. Examination of the heifer using rectal palpation and transrectal ultrasonography revealed enlargement of the right ovary and partial replacement of original tissue by multiple cysts of variable size. Treatment of the assumed follicularcystic ovary disease was unsuccessful. At slaughter 8 months later, the ovaries were examined pathologically and a granulosa cell tumor on the right ovary was diagnosed. Udder development and lactation in cattle is regulated normally hormonally. Follicular and cystic changes and granulosa cell tumors may also display hormonal activity. Therefore, we assume one or both of these could have been the cause of the unusual lactation in this case. We thus advise careful examination of the inner reproductive tract when facing the symptom of unusual lactation in unbred heifers.