A Case of Purulent Peritonitis Associated with Mucometra in a Female Cat

This case report describes the clinical, diagnostic imaging, surgical, and histopathological findings in a 4-year-old female domestic shorthair cat with marked uterine fluid accumulation, histopathological findings consistent with mucometra, and histopathological findings suggestive of purulent peritonitis. Based on the medical history, the cat had exhibited persistent estrus for six months and showed marked abdominal distension. Based on the clinical history, ultrasonographic findings, and physical examination, uterine fluid accumulation was diagnosed, and the differential diagnoses included mucometra, hydrometra, and pyometra. An ovariohysterectomy was performed, during which both uterine horns were found to be filled with fluid (650 mL) and exhibited pronounced symmetrical enlargement (4–5 cm in diameter). Histopathological examination of the submitted tissue sample was reported as compatible with mucometra. In addition, inflammatory cell infiltration observed in the serosa was considered suggestive of purulent peritonitis according to the pathology report. This case highlights the importance of considering mucometra in the differential diagnosis of queens presenting with persistent estrus behavior, progressive abdominal distension, and marked uterine fluid accumulation.