Hysterectomy for the Management of Chronic Endometritis With Keratinising Squamous Metaplasia in an Ovariectomised Pet Sow: A Case Report.

An 8-year-old female pig was presented to the University College Dublin Veterinary Hospital in February 2025 with chronic intermittent vulval discharge, depression and inappetence. The sow had previously undergone a laparoscopic bilateral ovariectomy in October 2023, with no complications; thus, the development of uterine disease would be highly unusual. Upon clinical examination, there was a moderate amount of mucopurulent vaginal discharge. Transabdominal ultrasonography was suggestive of endometritis secondary to cystic endometrial hyperplasia. A hysterectomy was performed, and histopathological examination of the uterus confirmed cystic endometrial hyperplasia, as well as chronic endometritis with marked keratinising squamous metaplasia of the endometrium and formation of keratinised 'uteroliths'. There was no evidence of any hormone-producing ovarian tissue in the abdomen. This squamous metaplasia and keratinisation have never been described before in sows, with uterine disease being incredibly rare in an ovariectomised animal with no ovarian remnants present. It may be prudent to consider ovariohysterectomy in sows, especially those with risk factors associated with chronic subclinical endometritis, for example, older animals.