Background and history

Prolapse of the vagina and cervix is more common prior to farrowing and may be seen in the last third of pregnancy including the pre-farrowing period in the farrowing house. It occurs normally in about one pregnancy in 200, usually in older sows from 5th parity onwards. It is a response to increased abdominal pressure together with a relaxation of the internal structures that support the cervix or the neck of the womb. Older sows that are heavy in pig, with large litters and in very good condition are also more likely candidates.

Clinical signs

In the early stages the protruding tissues appear between the lips of the vulva and return to their normal position when the sow stands. However with advancing pregnancy the prolapse may remain to the exterior and as soon as this occurs the animal should be removed from it's existing environment and loose-housed. The tissues become swollen with time.

Diagnosis

The clinical signs are obvious but occasionally can be confused with eversion of the bladder or vaginal polyps that may protrude from the vulva. Handling the tissues will allow differentiation.

Causes

• It occurs usually in older fatter sows that are heavy in pig.
• It is a response to increased abdominal pressure together with a relaxation of the internal structures that support the neck of the womb.
• It is more common in older sows.
• Sows housed on tethers with slippery floors are more prone.
• Stalls or tethers with floors that slopes too steeply to the rear predispose.
• High levels of starchy feed intake, produce excess fermentation and gas and an increase in abdominal pressure.

Prevention

The following factors need to be considered as causal or contributing to the problem:

• It is much more common in older sows than young ones.
• Sows housed on tethers on slippery floors are more prone.
• When sows lie down there is an increased abdominal pressure which tends to force the cervix or vagina to the exterior.
• Fat sows are more prone as are those carrying large litters.
• It is common in sows that are lying in confinement on a floor that slopes too steeply to the rear.
• High levels of feed intake, particularly food containing high starch materials, produce abnormal fermentation, excess gas formation and an increase in abdominal pressure.

Treatment

• Remove the sow to loose housing.
• If the prolapse remains when the sow is standing replace and pass a tape suture across the vulva.
• If the sow is at point of farrowing, the farrowing crate floor should be raised to slope towards the feeding trough by using raised floor boards. When the sow then stands or lies down the weight of the piglets inside pulls the womb forward to hold the vagina in. Under such circumstances the sow usually farrows normally.
• If the vagina remains prolapsed as farrowing approaches, the cervix will not open fully and both the sow and the litter are likely to be lost. In such cases a tape suture should be placed across the lips of the vulva to hold the prolapse in. As the sow reaches the point of farrowing it can be relaxed. This technique is described in chapter 15.