It is called prolapse of the oviduct to a condition sporadic that affects primarily during periods of start of the set, and is characterized by eversion accidental, irreversible oviduct through the cloaca.

This disorder usually arises as a direct result of the effort made by the hen during the commissioning. It is common after the expulsion of the egg. In chickens, it can be seen easily the protrusion of the organ to the outside.

In its early stages, the condition is accompanied by a very congested; however, if you do not take any corrective action in the following days, there may arise a situation of food, which causes the necrosis of the organ.

The oviduct is congested considerably and, in union with the cloaca, is ejected to the outside through the anus. If you do not act with due diligence, this can trigger an outbreak of cannibalism among the birds, that the individuals peck the mass evertida to cause the death of the hen.

Also, it is possible that the pecking of other chickens is a determining factor for the occurrence of prolapse. The birds that have received bites in the anal region can be due to inflammation and irritation, force ejecting the material is irritating, which can induce the cloaca is present in a case of prolapse.

Stafseth, Thompson y Grey (1932) de Michigan señalaron en su momento que el prolapso es un indicativo de cierta patología intestinal y, con menor frecuencia, del oviducto. La afección se da principalmente en las gallinas durante su primer año de producción de huevos.

Other researchers argue that the prolapse of the rectum, the oviduct, and the protrusion of the cloaca are often interrelated, indicating as the cause of intestinal inflammation caused by parasites and coccidios. 

Which play a significant role, and added that the minor occurrence of prolapse in adult birds could be linked to an acquired immunity to a simple physical resistance associated with age.

Brumester (1948) noted that some individuals have a predisposition to suffer from prolapse, either by a failure of estrogen (a sex hormone involved in the development of female secondary sexual characteristics) as well as by the production excessive androgen. A hormone that triggers the development of male secondary sexual characteristics.

This effect is probably the result of an inflammation and harmonious, which affects the ligaments of the oviduct, the separation of the pubic bones, the size of the cloaca and anus, as well as the elasticity of the abdomen.

On the other hand, Wheeler and Hoffmann (1948) believe that the prolapse and the snacks are related, to some extent, to the estrogen levels in the blood, and not with problems of constipation, intestinal irritation, and other related conditions.