Prolapsed rectum occurs worldwide and affects growers and finishers of all ages. The effects are red lining protrudes from anus or rectum.
- Causes of Prolapsed rectum >
- Effects of Prolapsed rectum >
- Diagnosis of Prolapsed rectum >
- Treatment & Control of Prolapsed rectum >
Causes of Prolapsed rectum
Rectal prolapse may occur in pigs or any age but is more common in males aged 14-16 weeks. There are a number of predisposing factors. A genetic predisposition has been identified.
In male piglets it may follow that result from straining the impac tion of phosphate crystals in the urethra. The condition has been reported to follow the inclusion of 20% excess lysine in the diet.
In weaned pigs although it may follow severe diarrhea straining is necessary before this occurs.
Mediation with Tylosin and to a lesser extent other antimicrobials may trigger prolapse which is Accompanied by soft faeces and by coughing.
The raised abdominal pressure or fighting causes alarm calls during the rectal mucosa to protrude visibly and it can be damaged when pigs are mixed and fight.
The hyperoestrogenism associated with zearalenone may predispose to the condition but rectal prolapse in sows in the farrowing sow usually follows or tethering or housing heavily gravid sows with the hind quarters lower than the body or hanging over a drop.
The prolapsed rectum may become reduced naturally, become strangulated, necrotic and drop off or be bitten off by the other pigs. Rectal stricture, or death from blood loss or peritonitis may all occur.
Effects of Prolapsed rectum
Rectal prolapse may be seen as a large reddish cylinder of the rectal mucosa protruding from the anus of the affected pig. It may be small (less than 2-10 cm in length) or large and oedematous.
Rectal prolapses are rapidly damaged by the animal as it backs into structures such as pen walls or by other pigs in the pen which bite it. It many cases, the first evidence that rectal prolapse has occurred in a group is the presence of blood on the mouths of a number of animals in the pen.
Lacerated or necrotic (dead and blackened) prolapses may also be found. Pigs may be found dead without the prolapse having been seen or, in some cases, the prolapse drops off before being noted. Where pigs are affected by zearalenone, there is usually vulval enlargement in females and some enlargement of the udder. Where diarrhea is associated with the cause, diarrhea is present in other animals in the group.
Diagnosis of Prolapsed rectum
Attention may be drawn to an affected pig as a result of biting or the prolapse may be seen. Early transient prolapses or letter may be visible as flashes of pink or red mucosa which are withdrawn after straining or defecation stops.
When pigs have died from rectal prolapses, the prolapse is generally visible and diagnosis is straightforward. If the animal is decayed however, the rectal mucosa balloons outward ballooning and this may be mistaken for prolapse. When the prolapse has dropped off or been chewed off in life or after death, examination of the rectum reveals the severed end.
The cause may be identified both in life or at post-mortem if diarrhea and straining are the cause, or if hyperoestrogenism is involved.
Treatment & Control of Prolapsed rectum
Animals must be separated from their fellows to avoid being killed. Small or transient prolapses may resolve spontaneously. In most cases, the prolapse must be surgically reduced (pushed back into the body) under local anesthetic and secured by a purse-string suture.
Where serious damage has occurred or where the prolapse can not be reduced manually, it must be amputated surgically under local anesthetic after the portion to be retained has been sutured in place. Animals may be treated in their groups by the insertion of an 18-20 cm helical corrugated plastic tube (1.5 cm in diameter and fatteners for weaners and sows for 2-3cm diameter) into the prolapse. Heavy duty rubber bands are placed over the anal prolapse near the ring. Tube prolapse and drop off after 5-7 days.
Affected animals or slaughter weight may be penned separately and transported for slaughter, but extensively and irreparably-damaged animals should be slaughtered humanely.
