Merck Manual

Please confirm that you are a health care professional


Prolapse of the Oviduct in Poultry


Rodrigo A. Espinosa

, DVM, MAM, DACPV, Aviagen, Inc

Last full review/revision Aug 2019 | Content last modified Sep 2019
Topic Resources

When an egg is laid, the vagina everts through the cloaca to deliver the egg. If there has been injury to the vagina, such as from a large or double-yolk egg, or if the hen is fat, the vagina may not retract immediately, leaving it exposed for a short time. This may result in cannibalism. When the protruding organ is pecked by other hens, the complete oviduct and parts of the adjacent intestinal tract may be pulled from the abdominal cavity (“peckout”). Bleeding from the vent is observed as a result of pecking. Alternatively, the vagina swells, cannot retract, and remains prolapsed (“blowout”). The hen dies from shock.

Prolapse has been associated with:

  • excessive/premature photostimulation

  • poor body weight uniformity

  • early laying (inadequate body size)

  • large eggs

  • double-yolked eggs

  • obesity

Cannibalism may be prevented by beak trimming, managing light intensity, maintaining appropriate stocking density, and avoiding nutritional deficiencies.

Others also read

Also of Interest


View All
Infectious Laryngotracheitis
Infectious Laryngotracheitis
Broilers infected with infectious laryngotracheitis virus.