Description:
A 22‐month‐old female Mongolian gerbil presented with palpable cranial abdominal masses. At initial presentation, no clinical signs were associated with the masses and the owner elected to monitor the gerbils’ condition. Abdominal distention developed over the following eight months and was progressively associated with altered demeanour, reduced mobility and increased respiratory effort. An exploratory laparotomy identified left‐sided ovarian masses and right‐sided ovarian cysts. A bilateral ovariectomy was performed. No other changes were noted. Recovery from surgery was uneventful, but the gerbil died six weeks later. Histological findings were consistent with a unilateral ovarian interstitial cell tumour accompanied by contralateral ovarian cysts and interstitial cell hyperplasia. To the authors’ knowledge, this is the first report of an ovarian interstitial cell tumour in a Mongolian gerbil.