Urachal Cyst in a Bitch


  • Fernanda Campos Hertel Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Aline Silvestrini da Silva Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Gabriela Castro Alves Evangelista Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Amanda Pereira dos Anjos Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Andreia Correia Araújo Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Evandro Silva Favarato Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Tatiana Schmitz Duarte Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.
  • Emily Correna Carlo Reis Departamento de Veterinária, Universidade Federal de Viçosa (UFV), Viçosa, MG, Brazil.




Background: The urachus is a tubular structure continuous with the urinary bladder and the allantois in foetal mammals. It serves as a communication between these two structures. At birth, it loses its function and undergoes atrophy by fibrous proliferation within the lumen. When this atrophy process fails at some point, congenital anomalies of the urachus occur. These anomalies are rare in animals, and to our knowledge, the urachal cyst has not yet been described in dogs. The present work is unique in that it reports a case of this congenital defect in a dog. Our aim is to increase awareness and to discuss the clinical presentation, the imaging techniques used, and the final diagnosis of this anomaly.

Case: A bitch Pit Bull, 3-year-old, was presented for veterinary assistance to investigate recurrent pseudopregnancy and an irregular estrous cycle. The animal presented in good bodily condition, and the white blood count and clinical biochemistry were normal. At ultrasound, 2 tubular structures, filled by an echogenic fluid mimicking uterine topography, were found extending through the umbilical and hypogastric regions. No alterations in structure, echogenicity or echotexture of the other organs were observed, including the ovaries and uterus. On exploratory laparotomy, a cystic structure was found, with 2 segments: the larger one was on the left side, attached to the apex of the bladder by its caudal portion; the other was on the right side, attached to the spleen by its cranial portion and to the apex of the bladder by its caudal portion in connection with the left segment. The ovaries, uterus and uterine horns showed no macroscopic alterations. The structure was removed, and after analysis (macroscopic morphology, wall histopathology and biochemistry of the contained fluid), it was determined to be a urachal cyst. The animal recovered uneventfully.

Discussion: Ultrasound is an important tool for the evaluation of reproductive cycle physiology and its pathologies. At first, the owner’s complaint justified a fairly straightforward evaluation and clinical management of pseudopregnancy in a very healthy animal based on the history and clinical and complementary exams. However, ultrasound examination revealed two tubular structures filled with echogenic fluid in the lower abdomen. This made the case more complex, as these were interpreted as uterine horns by three different veterinarians, leading to the possibility of pyometra. The management of this condition must be cautious, since the animal's condition could rapidly deteriorate, necessitating an exploratory laparotomy. Based on the clinical presentation, macroscopic anatomy, fluid biochemistry and histological evaluations, the diagnosis of urachal cyst was proposed. Congenital anomalies occur when the urachus fails to obliterate. Four types can be found: patent urachus, urachal sinus, urachal diverticulum and urachal cyst. The urachal cyst occurs when the urachus encompasses a cyst-like structure that is closed to the umbilicus and the bladder lumen. The urachus becomes a cystic structure since its epithelium is still intact, active and accumulating fluid, like the one analysed in this report. Most urachal cysts in humans remain asymptomatic, but when infected, they can cause focal or diffuse peritonitis and an acute abdomen. Although rare, urachal cysts can develop malignant transformation. The combination of nonspecific symptoms and the infrequent occurrence of this anomaly make its diagnosis a difficult challenge. It is commonly an incidental finding like the case reported here. Therefore, diagnostic imaging techniques, especially ultrasound, are essential for the diagnosis. To our knowledge, this is the first case report of a urachal cyst in a dog. This rare anomaly of the urachus was an incidental finding in the investigation of the reproductive problems of a female dog.


Download data is not yet available.


Aleixo G.A.S., Souza M., Mendes Z.F., Baraúna Jr. D., Leite J.E.B., Tenório A.P.M. & Coelho M.C.O.C. 2007. Persistência do úraco em gato: relato de caso. Arquivo Brasileiro de Medicina Veterinária e Zootecnia. 59(4): 943-947.

Brennan K., Johnson P., Curtis H. & Arnason T. 2019. Urachal mucinous cystic tumor of low malignant potential with concurrent sigmoid colon adenocarcinoma. Case Reports in Gastrointestinal Medicine. 2019: 1434838. https://doi.org/10.1155/2019/1434838

Danial A.K., Tarabishi A.S., Aldakhil A., Alzahran A., Najjar O. & Ayoub K. 2019. Acute abdomen due to an infected urachal cyst in a 5-year-old female: case report. Journal of Surgical Case Reports. 5: DOI:10.1093/jscr/rjz156.

Fayrer-Hosken R.A., Mahaffey M., Miller-Lebl D. & Caudle A.B. 1991. Early diagnosis of canine pyometra using ultrassonography. Veterinary Radiology. 32: 287-289.

Groesslinger K., Tham T., Egerbacher M. & Lorinson D. 2005. Prevalence and radiologic and histologic appearance of vesicourachal diverticula in dogs without clinical signs of urinary tract disease. Journal of the American Veterinary Medical Association. 226(3): 383-386.

Ilica A.T., Mentes O., Gur S., Kocaoglu M., Bilici A. & Coban H. 2007. Abscess formation as a complication of a ruptured urachal cyst. Emergency Radiology. 13(6): 333-335.

Laverty P.H. & Salisbury S.K. 2002. Surgical management of true patent urachus in a cat. Journal of Small Animal Practice. 43(5): 227-229.

Lojszczyk-Szczepaniak A., Smiech A. & Wojnowski T.A. 2015. Congenital urachal diverticulumin dogs: a case report. Medycyna Weterynaryjna. 66(6): 421-424.

Macedo J.T.S.A., Lucena R.B., Giaretta P.R., Kommers G.D., Fighera R.A., Irigoyen L.F. & Barros C.S.L. 2011. Defeitos congênitos em bovinos da Região Central do Rio Grande do Sul. Pesquisa Veterinária Brasileira. 31(4): 297-306.

Marques L.C., Marques J.A., Marques I.C.S. & Teixeira M.C.A. 2010. Dilatação cística do úraco e uroperitônio em touros: relato de cinco casos. Arquivo Brasileiro de Medicina Veterinária e Zootecnia. 62(6): 1320-1324.

Mrad Daly K., Ben Rhouma S., Zaghbib S., Oueslati A., Gharbi M., Nouira Y. 2019. Infected urachal cyst in an adult: A case report. Urology Case Reports. 26: 100976.

Naiditch J.A., Radhakrishbnan J. & Chin A.C. 2013. Current diagnosis and management or urachal remnants. Journal of Pediatric Surgery. 48(10): 2148-2152.

Osbek S.S., Pourbagher M.A. & Pourbaher A. 1991. Urachal remnants in asymptomatic children: gray-scale and color doppler sonographic findings. Journal of Clinical Ultrasound. 4: 218-222.

Prakash M.R., Vijayalaxmi S.V., Maitreyee R. & Ranjit K.P. 2014. Complex mucinous cystadenoma of undetermined malignant potential of the urachus: a rare case with review of the literature. Malays Journal of Pathology. 36(2): 145-148.

Pretzer S.D. 2008. Clinical presentation of canine pyometra and mucometra: A review. Theriogenology. 70(3): 359-363.

Remedios A.M., Meddleton D.M., Myers S.L., Outerbridge C.A. & Arnold P.M. 1994. Diverticula of the urinary bladder in a juvenile dog. The Canadian Veterinary Journal. 35(10): 648-650.

Rhudd A., Moghul M., Nair G. & McDonald J. 2018. Malignant transformation of a urachal cyst-a case report and literature review. Journal of Surgical Case Reports. 2018(3): rjy056.

Rocha T.G., Teixeira L.G., Seppa G.S., França T.N. & Brito M.F. 2007. Fístulas e outras anomalias congênitas dos tratos digestivo e urinário em um potro. Ciência Rural. 37(5): 1488-1491.

Sato H., Futura S., Tsuji S., Kawase H. & Kitagawa H. 2015. The current strategy for urachal remnants. Pediatric Surgery International. 31(6): 581-587.

Schlafer D.H. & Giffor A.T. 2008. Cystic endometrial hyperplasia, peseudo-placentational endometrial hyperplasia, and other cystic conditions of the canine and feline uterus. Theriogenology. 70(3): 349-358.

Tazi F., Ahsaini M., Khalouk A., Mellas S., Stuurman-Wieringa R.E., Elfassi M.J. & Farih M.H. 2012. Abscess of urachal remnants presenting with acute abdomen: a case series. Journal of Medical Case Reports. 6: 226-232.

Vieira Jr. E.S., Abreu R.A.A. & Speranzini M.B. 2007. Cisto de úraco em adultos simulando abdômen agudo. Revista do Colégio Brasileiro de Cirurgia. 34(1): 67-68.

Wan Y.L., Lee T.Y., Tsai C.C., Chen S.M. & Chou F.F. 1991. The role of sonography in the diagnosis and management of urachal abscesses. Journal of Clinical Ultrasound. 19(4): 203-208.

Yoo K.H., Lee S.J. & Chang S.G. 2006. Treatment of infected urachal cysts. Yonsei Medical Journal. 47(3): 423-427.

Yu J.S., Kim K.W., Lee H.J., Lee Y.J., Yoon C.S. & Kim M.J. 2001. Urachal remnant diseases: spectrum of CT and US findings. RadioGraphics. 21(2): 451-461.



How to Cite

Hertel, F. C., da Silva, A. S., Alves Evangelista, G. C., dos Anjos, A. P., Araújo, A. C., Favarato, E. S., Duarte, T. S., & Carlo Reis, E. C. (2019). Urachal Cyst in a Bitch. Acta Scientiae Veterinariae, 47. https://doi.org/10.22456/1679-9216.97758

Most read articles by the same author(s)