Midline Cysts of Colliculus Seminalis Causing Ejaculatory Problems in Stallions

Malgorzata A. Pozor, Margo L. Macpherson, Mats H. Troedsson, Claudia Klein, Mohamadou Diaw, Claus Buergelt, Liane Dillon

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Cystic structures are often seen during ultrasound examination of the internal genitalia of stallions. They are located between the ampullae of deferent ducts, either within the urogenital fold, or under the isthmus of the prostate (uterus masculinus). Occasionally, cystic dilatations are also found more caudally, behind the prostate, at the colliculus seminalis (urethral cyst, utriculus masculinus). These cysts are detected less frequently during routine examinations, possibly because of the fact that this area is screened less carefully for the pathologies than the more proximal portion of the internal reproductive tract of stallions. We have recently noticed that many stallions with ejaculatory problems have large cysts at the colliculus seminalis. This article describes the typical clinical presentation of these cases, diagnostic procedures, and management. In addition, we discuss the discrepancies in the currently used terminology pertinent to this condition, as well as introducing a new term, which seems to best describe the root cause of this disorder. Finally, this article presents new diagnostic and therapeutic options used in human medicine in similar cases, and proposes to investigate the applications of these methods in veterinary medicine.

Original languageEnglish
Pages (from-to)722-731
Number of pages10
JournalJournal of Equine Veterinary Science
Issue number12
StatePublished - Dec 2011


  • Ejaculatory dysfunction
  • Midline cyst
  • Stallion
  • Uterus masculinus
  • Utriculus

ASJC Scopus subject areas

  • Equine


Dive into the research topics of 'Midline Cysts of Colliculus Seminalis Causing Ejaculatory Problems in Stallions'. Together they form a unique fingerprint.

Cite this