11/1/2021:
Torsion of parts of the intestines and organs such as the spleen and liver, is a well-known cause of acute mortality among sows. In recent years, GD pathologists have encountered more and more cases of liver lobe torsion upon pathological examination. This diagnosis was made 21 times in 2020, versus 19 times in 2019 and 12 times in 2018. Our Belgian colleagues in Flanders (DGZ) have also reported an increase in recent years.
Increased losses at sow farm
A sow farm had suffered increased losses. In the first quarter of 2020, the farm submitted five dead sows to the GD laboratory for pathological examination. Blood tests were also carried out to check for any metabolic diseases in a number of living sows. The results of the pathological exams varied. Three of the sows had suffered torsion in a liver lobe. The abdomen contained a great deal of bloody fluid, probably caused by a rupture in the liver. Chronic brain damage was discovered in two sows, which could not be linked directly to the acute mortality at the farm. There were no clear indications for any intoxication or infectious disease. The blood tests did however indicate issues with calcium absorption, but also with poor feed intake in general. Blood samples submitted for a number of the sows clearly showed serious liver issues. Based on the diagnosis of liver lobe torsion and the results of the blood tests, it was concluded that this farm primarily had liver problems.
Explanation for torsion
Repeated stomach dilatation is the most obvious cause of liver lobe torsion. The stomach becomes extremely dilated due to pigs only being fed once a day, large volumes of wet feed, or gas formation, for example. This dilatation of the stomach is believed to damage the liver ligaments, increasing the risk of torsion, which in turn results in obstruction, tears and fatal haemorrhaging.
Evaluation of feeding systems
Due to the relationship with the stomach, thorough evaluation of the feeding system and feed management is advised in the case of liver lobe torsion. After all, hepatic torsion may be caused by problems with the feeding system throughout the farm. When there are excessive losses of sows, liver lobe torsion must be included explicitly as cause of death in the differential diagnosis. A number of risk factors for the occurrence of liver lobe torsion include feeding only once a day, uncontrolled and irregular feed intake, and the feeding of (large volumes of) wet gruel with a high liquid content. Sows who have recently farrowed are believed to be at greater risk.
Theo Geudeke, pig veterinarian at GD
“This is an increasingly common occurrence”
“The acute mortality at this sow farm was striking. The reason behind this notification was not immediately clear. In consultation with the farmer’s own veterinarian therefore, five sows were submitted for pathological examination and further examination. Three of the sows were found to have liver lobe torsions. We generally see that ten to twenty times a year, which made it very remarkable to suddenly receive three animals suffering from this disorder from a single farm. That is no longer simply bad luck, but rather something is wrong.
On further examination, there was a great deal of bloody fluid in the abdomen. In a liver lobe torsion, the liver partially twists, pinching that part of the organ, causing it to swell and eventually tear. The animals then die of internal bleeding. Such torsions were a very rare occurrence in the past. Around three years ago, we were suddenly confronted with four or five of such cases within a month. They have become increasingly common since then, and our colleagues in Belgium concur. Liver lobe torsions are often seen in large sows. The liver is suspended next to the stomach, by means of ligaments. When the stomach regularly swells and then shrinks again, those ligaments become weakened. This results in instability in fixation of the liver. It may cause torsion, which will not naturally right itself.
The issue of increased losses can be a cause for concern at some sow farms. Effective diagnosis is essential, so the correct preventative measures can be taken. That is not easily done at a sow farm; pathological examination is the only way of clearly identifying the cause. The number of liver lobe torsion cases seems to be on the increase, and we therefore need to stay alert.
Unlike our farmed pigs, wild pigs will graze for their food all day long. Many sows are only fed once a day, and some animals also feed very greedily. When the sows are fed liquid gruel in particular, the stomach is filled very quickly. If a sow is fed 3 kilos of dry feed and 9 litres of water all at once, and greedily eats and drinks it all, the stomach will swell considerably. Liver lobe torsions are mainly seen in sows and less so in finishers. However, other sections of the digestive tract can also become twisted. Stomach and intestinal torsions also seem to be on the increase, in pigs of varying ages. All the more reason to take a good look at the feeding regime on the farms. Many pig farmers only feed once a day in order to avoid disturbance in the barn as much as possible. We did indeed advise them to do so in the past, precisely for that reason. However, splitting the feed over a number of feeding times a day is a better idea in order to combat the torsion problems.”
“Liver lobe torsion and intestinal torsion can often be prevented by feeding a number of times a day”
Pig veterinarian
“Independent research makes the discussion easier”
“GD has conducted research following increased losses at a sow farm. The necessary measures were taken at this farm once it became apparent that liver lobe torsion was the problem. Liver lobe torsion caused by stomach or intestinal torsion is generally food related. The sow farm in question switched their feeding regime to a number of times a day instead of once a day. The sows were still fed gruel, as before, though in smaller portions. This allowed the farm to take control of the problems caused by intestinal and hepatic torsion.
My colleagues and I are under the impression that we are seeing higher losses in sows fed gruel. While we did encounter problems with stomach and intestinal torsion in the past, including hepatic torsion, we feel that such problems are more common nowadays. Particularly at those farms which feed large volumes, such as gruel, to the sows once a day. When we are inclined to think that this is the cause, it is time to discuss the matter with the farmer. Feed management is then the first point of attention to be discussed. Farmers will not always submit an animal for pathological examination immediately. When there are continued losses, even after trying a number of measures, they become more willing to submit animals, while we have also been able to exclude a number of possibilities.
Submitting one or more animals can provide certainty when there are problems. Thanks to the GD research, I have an independent party to back me up, and indicate where the problem lies. That makes the discussion easier with the farmer, and sometimes also the feed adviser. In such cases, I regularly call the Veekijker for advice. We can then discuss what action should be taken for such results, and how to interpret them. It’s always nice to be able to consult. Once you’ve been able to provide more information on the farms, by telephone, the results of the examination also become more focused for the GD Veekijker veterinarians. Vice versa, we get more advice on the approach and any additional ways in which feed management can contribute.”
Our expert Theo Geudeke