Cystocele is a chronic condition mostly seen in humans, which defines as the protrusion of the bladder into the vaginal wall. Generally, vaginal prolapse includes bladder prolapse or cystocele, rectal prolapse or rectocele, and uterus prolapse. This condition is very rare in veterinary medicine and, as a consequence of dystocia, constipation and forced breeding are performed. In this case, report a 5-year-old mixed breed intact female dog and non-pregnant was diagnosed with cystocele using diagnostic imaging and clinical examinations, furthermore was treated with cystopexy surgical techniques and, a necrotic segment in the ventral side of the bladder was seen, which was treated with partial cystectomy. cystocele is a condition mostly seen in humans and, according to our knowledge, there is only one previous report of occurrence in animals.