Bpex.org.uk

NADIS Pig Health - October 2006
Rectal Prolapse
Compared to other farm species, the pig appears to beparticularly vulnerable to prolapse of the rectal tissue through theanus, which can be seen in any age group from as early as 1-2days old up to adults.The fundamental cause of the prolapse is anincrease in abdominal pressure, forcing a breakdown in the weakmuscular support mechanism of the pelvis, which normallyretains the rectum in place. There may well be both breed andgender differences in the vulnerability of individuals to prolapseoccurring.
Fig. 1: A typical rectal prolapse in a weaner.
Causes of Prolapse
The following list provides an outline of the most common
causes of prolapse, as seen in commercial pig farms:
1. Diarrhoea or dysentery - particularly associated with large
intestine inflammation that may include rectal inflammation(e.g. Salmonella, Swine Fever).
2. Constipation most likely to be seen in the adult close to 3. Parturition - as a result of excessive straining.
4. Water shortage - leading to reduce water content of the faeces and increase straining to pass.
Fig. 2: Rectal prolapse in a sow post farrowing.
5. Medicines. Certain antibiotics (Tylosin, Lincocin) have been associated with oedema (swelling) of the lining of the rectumand subsequent prolapse. This is most likely seen with highdoses.
6. Toxins. Some mycotoxins from feed or straw can be associated with rectal swelling and straining.
7. Rectal damage e.g. as a result of boars riding each other.
8. Coughing. The process of coughing causes an increase in abdominal pressure and, in some cases, this may be sufficientto push out the rectum. Many animals will expel faeces asthey cough and the rectal lining will penetrate through theanus. In extreme cases, it does not return and remainsprolapsed.
9. Fast growth. Prolapsing can often be a problem in fast Fig. 3: Rectal stricture – a common sequel to rectal prolapse
growing pigs, particularly from 30-60kg on very high densitydiets.
2. It remains outside the anus and, due to the 10. Variable temperatures. Pigs have a poor ability to control their constrictive effect on blood and fluid drainage, body temperature and tend to be adversely affected by it generally swells up. It is thus easily damaged variation in the ambient temperature and prone to chilling.
by trauma on pen divisions, feeders etc.
The consequence is huddling and piling on top of one 3. It is eaten by other pigs in the pen. It is notanother. If a pig then coughs while another is lying on top of uncommon to find blood in a pen and around it, the abdominal pressure will be even higher than normal and the only place that the pressure can be relieved is at the prolapse in any other animals i.e. the prolapse will have been completely chewed off.
Consequences
Once a prolapse has occurred, a number of events may follow: a. No effect - particularly if the prolapse returns 1. It rapidly returns into the anus.
b. Slow dying off of the prolapsed material over several weeks body condition whilst the abdomen continues to with the chances of secondary infection arising from rotting swell and reabsorbtion of bile in the gut produces clinical jaundice. Such animals are largely c. Rectal stricture. The prolapse resolves but the scar tissue left forms a ring of slowly constricting tissue that eventually blocks the rectum leading to a “blown up” pig (Fig 3). Suchanimals require euthanasia.
Prevention
Clearly, prevention of rectal prolapses rests in being
able to identify and correct the cause of the Any animal noticed with a prolapsed rectum should be isolated away from other pigs. If it is of slaughter weight, it canimmediately be despatched for slaughter with a Schedule 18 casualty slaughter owner’s declaration. It should be transported in It is extremely difficult to quantify the financial losses associated with rectal prolapse as in mostcases it is underlying disease which precipitates the If swollen but undamaged, it may be possible to replace the prolapse and it is the cost of the disease itself, prolapse by sprinkling sugar or salt on it, leaving it 30 minutes and then gently pushing it back in. The osmotic effects of thesalt/sugar draws out the fluid and shrinks the prolapse.
However, where there is no underlying disease aprolapse in growing pigs is the result of high It may be necessary to place a purse string suture around the anus growth rates it is possible to give examples. A farm typically affected can lose 2% of all growing pigs asa result of prolapse/stricture at an average cost of In a large animal (sow), a rubber washing up glove placed over an say £60/head (including lost profit opportunity).
undamaged prolapse may exert enough pressure to shrink the Therefore for a 500 sow breeder feeder farm over tissue and return it inside the rectum.
a year this could add up to a loss of 230 growingpigs worth £13,800/year. This cost would then Where a prolapse is damaged and clearly not in a state to replace, have to be offset by the cost of slowing growth to it must be amputated.The easiest way to achieve this is to insert prevent prolapse. For example if 50gm/day daily a pipe (1" diameter for a growing pig, 11⁄ live weight gain was sacrificed between 30 and prolapse and tie a ligature around the prolapse baring down onto 100kg this would add 6 days to reach slaughter the pipe. It is necessary to tie the pipe in with the loose ends of weight; with additional feed and facility costs this the ligature. This will cut the blood supply to the prolapsed would incur a cost of at least £1/pig. On the material and allow it to dry up and drop off, usually in less than model 500 sow breeder feeder farm this would 7 days, although it may be necessary to re-tie the ligature after add costs of approximately £11,000/yr. (If space 3-4 days as the tissue shrinks. If corrugated pipe is available (e.g.
does not permit retention for this extra 6 days then electrical conduit), heavy duty rubber bands or even lamb up to 3kg would be lost from the carcass weight elastrator rings can be used as a ligature.
and the losses would triple). Of course, theabsolute financial cost of incurring/preventing In all cases, antibiotic cover should be provided.
rectal prolapse would have to be viewed in the Where damage is so great that intestinal tissue prolapses through light of the welfare cost to the animals affected.
the open wound immediate humane slaughter is required.
Similarly where a rectal stricture has resulted, the animal will lose NADIS Health Bulletins are designed to improve farm income, animal health and welfare by promoting
disease control and prevention.
Discuss how health planning can improve the profitability of your farm with your veterinary surgeon.
NADIS is supported by BPEX EBLEX HCC QMS Elanco Animal Health and MLC.

Source: http://www.bpex.org.uk/downloads/295036/283272/Rectal%20prolapse.pdf