Cystic endometrial hyperplasia and chronic endometritis in a chinchilla

A 4-year-old nulliparous sexually intact female chinchilla (Chinchilla lanigera) was evaluated because of a 2-month history of blood being sporadically observed in its cage.

Results of physical examination of the chinchilla were unremarkable except for the presence of blood-stained fur around the perineum. There were no external lesions to account for the bleeding. Findings on urinalysis, bacteriologic culture of urine, and whole-body radiography were unremarkable. The chinchilla's littermate had been evaluated because of similar clinical signs 2 years earlier, and these signs resolved following ovariohysterectomy.

Ovariohysterectomy was performed, and gross changes were not observed in the reproductive tract. However, microscopic examination revealed multifocal cystic dilation of the endometrial glands, foci of microhemorrhage, and chronic suppurative inflammation consistent with a final diagnosis of cystic endometrial hyperplasia and chronic endometritis. Clinical signs did not recur.

Cystic endometrial hyperplasia has been documented in a variety of animals, but to the authors' knowledge, this was the first reported case in a chinchilla. Cystic endometrial hyperplasia and chronic endometritis should be considered as a differential diagnosis in an adult sexually intact female chinchilla with a history of suspected hemorrhagic vaginal discharge, suspected hematuria, or hemorrhage from an unknown source.