Exuberant mucometra associated with atresia of the cervix in a queen.

This short communication reports the clinical, ultrasonographic and histopathological findings in a cat with atresia of the uterine cervix and mucometra. After 6 months of continuous oestrous behaviour, a remarkable abdominal enlargement was observed in a 14-year-old queen. A presumptive diagnosis of mucometra was concluded after the ultrasound evaluation and based on clinical signs and blood analyses. Ovariohysterectomy revealed a notable symmetrical distension (4-5 cm in diameter) of both uterine horns that were filled with fluid (690 ml); microbiological analyses confirmed the aseptic nature of the uterine fluid. Ovarian follicular cysts and cystic subsurface epithelial structures, >1.5 cm in diameter, were present in both ovaries and no corpora lutea were observed. Gross and microscopic evaluation of the uterus confirmed the development of cystic endometrial hyperplasia and the absence of an internal cervical os. The endometrial hyperplasia and mucometra could have developed as a consequence of repeated oestrogenic stimulation.