Hematocolpus in two bitches with a history of GnRH treatment to postpone puberty

Abstract

Two mixed-breed bitches (18 and 19 months), 1 year before treated with deslorelin acetate implant to postpone puberty, were hospitalized and monitored during their first heat. The heat was visible to the owners for the vulvar swelling but in both cases no vulvar bloody discharge was observed. The following diagnostic procedures were employed: physical genital tract examination, vaginoscopy, vaginal cytology, endocrine assay, ultrasound and X ray using vaginal infusion of iodum and pneumobladder as positive and negative contrasts. In bitch 1, vaginal cytology and progesterone levels confirmed the presence of an ovulatory “dry” oestrus. Ultrasound showed preovulatory follicles and, in the following days, transition to corpora lutea. The caudal abdomen presented a large ovoid cystic structure filled with echoic fluid, next to the bladder. Radiographic scans demonstrated a normal bladder profile, while the contrast medium failed to enter into the cranial vagina. On the basis of these findings, the bitch 1 was submitted to laparotomy 10 days after the end of oestrus. A vaginal dilatation (10x5 cm), from which brown fluid was aspirated, was found and resected together with uterus and ovaries. Bitch 2 had the same diagnostic route and findings but was laparotomized 3 months after the heat. During this period no spontaneous regression of the lesion was observed. At laparotomy, the vaginal dilatation (8x4 cm) was only aspirated and the bitch regularly neutered. In both cases, cytology of the fluid taken from the vaginal sac revealed superficial epithelial cells and abundant degenerate red blood cells. Histology (bitch 1) confirmed the vaginal origin of the dilatation and revealed a Gartner duct cyst. The abnormality (hematocolpus) probably originated by an inadequate drainage of proestrous bloody discharge for a vaginal obstruction. A congenital origin of the lesion was unlikely; it was strongly suspected that the treatment of the prepubertal bitches interfered, by an irreversible way, with the normal development of the vagina.