Avian Cloacal Prolapse Study Guide

Overview and Clinical Importance

Cloacal prolapse (also termed vent prolapse) is a serious and potentially life-threatening emergency in avian medicine where internal tissues of the cloaca protrude through the vent opening. The cloaca (Latin for "sewer") is the common terminal chamber for the gastrointestinal, urinary, and reproductive systems in birds. Prolapsed tissues may originate from the cloacal wall itself, the oviduct (uterus), or the intestinal tract. This condition requires immediate veterinary intervention as exposed tissues are at risk of trauma, desiccation, infection, and ischemia.

Cloacal prolapse is particularly prevalent in certain psittacine species, especially cockatoos and African grey parrots, and is strongly associated with both reproductive and behavioral factors. Understanding the anatomy, etiology, differential diagnosis, and treatment options is essential for the NAVLE examination.

Anatomy of the Avian Cloaca

The cloaca is divided into three distinct chambers separated by mucosal folds. The mnemonic "CUP" (Coprodeum, Urodeum, Proctodeum) helps remember the proximal-to-distal arrangement.