[Ovarian tumor in a koi carp (Cyprinus carpio): Diagnosis, surgery, postoperative care and tumour classification]

Although ovarian tumour in the koi (Cyprinus carpio) does not appear to be an uncommon condition, its occurrence and therapy has rarely been reported. In the present case, the decision for surgery was based on clinical and sonographic findings of an intracoelomic mass. We used tricaine methansulfonate for the anaesthesia. Laparotomy was performed by ventral access and an ovarian tumour of 12-cm diameter was removed. The wound was sutured in two layers using Vicryl®. In addition to the application of an analgesic, an antibiotic and vitamins, the postoperative conditions the patient was kept under were adapted to support wound healing. The fish recovered uneventfully and was clinically healthy during the 16-month observation period. Based on the histological findings, the tumour was diagnosed as a thecoma. Investigations using antibodies against vimentin, cytokeratin, S 100 and glial fibrillary acidic protein (GFAP) failed to provide reliable results.