RESUMEN
Diseases related to the urogenital system in both males and females, are common in clinical routine of smallanimal and represents important causes of morbidity and mortality in dogs and cats. Pyocolpos is a cysticdilatation of the vagina due to the accumulation of pus resulting from the genital tract obstruction. The maincause of obstruction is imperforate hymen, transverse vaginal membrane, or vaginal atresia.We present a caseof a three-year-old female Pinscher with a history of constipation for four days, even after administration oflaxatives and enema, and estrus for ten days without a report of cover. Physical examinations were performed,which revealed increased abdominal size. Ultrasound confirmed the presence of large amounts of vaginal fluid.Exploratory laparotomy was performed, which confirmed the diagnosis of pyocolpos. Although pyocolposis a rare congenital malformation in female domestic animals, this report of its existence underscores theimportance of more accurate clinical research when increased abdominal size is noted by veterinarians.