Pregnant ewes experience a tremendous strain on their abdominal muscles and tendons as their lambs grow, especially during the last few weeks of pregnancy. The abdominal muscles and tendons are attached to the ribcage, vertebrae and pelvis (grey lines in picture) with the muscles and tendons forming a hammock (pink) that supports the abdominal organs. As the lambs grow, this hammock stretches and gets thinner and is under more pressure. The prepubic tendon (red X in the picture) is made up of the tendons of multiple abdominal muscles and attaches along the lower rim of the pelvis, just above the udder. This tendon is under a lot of strain and in some ewes, it fails, leading to a prepubic tendon rupture.
A prepubic tendon rupture is a type of body wall hernia, but unlike umbilical and inguinal hernias, the possibility of strangulation of abdominal organs is typically not a concern. Prepubic tendon ruptures are problematic because they cause functional problems for the ewes.
This condition happens to different degrees, varying from a total failure where the udder and abdomen between the back legs just hangs down to the ground, with no support, to a one-sided tear where one side of the abdomen is still supported but the other is not, as in the example below.
This heavily pregnant ewe’s abdomen all of a sudden looked lopsided. In the photo above you can see that the left side of her abdomen hangs lower than the right. Also, note the shape of the left side of her abdomen, it just hangs down low when compared to the right side that is being pulled up into a rounder shape. Note her udder; it hangs down lower on the left and appears fuller on this side. The right side of her udder is being pulled up towards her spine by the normal abdominal muscles on this side, while the left side has lost its support. This ewe has trouble moving around as she has this big belly that hangs down right in front of her knee.
Here is the same ewe from the side. Note the hairless area visible in front of her udder, this area should be behind her leg and above her udder, note how low and far forward it sits, as it is not being pulled back and up.
Below are photos of the same ewe before her tendon rupture. You can see that the bottom of both sides of her abdomen are on the same level, and even though the two sides are not identical, both are being pulled up into a roundish shape. Her udder is nice and symmetrical. From the side the bald area is barely visible, and definitely sits higher than her udder, there is also more room between her leg and her abdomen. There is a nice upward curve of her abdomen towards her tail.
With prepubic tendon ruptures, you typically see more of the udder visible in front of her leg and that it hangs much lower than before. One-sided body wall ruptures will often lead to displacement of the udder, where the bottom of the udder is suddenly visible on the side of the ewe. You can often also see that one side of the abdomen hangs a lot lower than the other when looking from behind.
Unfortunately, this condition is not treatable and does not resolve. The long-term prognosis for the ewe is poor and she should not be bred again. A lot of ewes with this condition are able to raise their lambs successfully to weaning. Watch her carefully and make sure she is able to graze and move around comfortably. If a prepubic tendon rupture is suspected, check with your vet, and limit activity. If you use bunk feeders, you might have to feed affected ewes separately as they are not able to compete well with the other ewes and you do not want to risk her getting pregnancy toxemia too.
If her udder ends up in a very exposed position or hangs down very low, you might have to use a belly band (think ewe bra) to lift and protect her udder. Ewes are often able to lamb naturally, although assistance is usually necessary due to the compromised abdominal muscles. A cesarean section may be necessary in some cases. In severe cases the ewe’s quality of life can be very compromised and euthanasia might be the best solution.
This ewe was able to have all three her ewe lamb unassisted three days after her tendon rupture. She is raising her lambs. You can see in the photo below that her udder is still displaced, but her lambs are able to figure out how to navigate her lopsided udder.
Depending on the severity of the rupture, extra care may be needed for the lambs to be sure they are able to reach the displaced udder. Start by watching the ewe and her lambs for 15 -30 minutes and see what they can figure out by themselves. You can milk the ewe and tube feed colostrum to the lambs initially to buy some extra time for the lambs to figure things out. You might have one or more lambs that struggle and need to be supplemented with a bottle.
Be sure to keep a close eye on this ewe and her lambs until weaning. Watch the lambs nurse and weigh them from time to time to make sure they are gaining weight. Watch the ewe and make sure she can keep up with the flock and that she is able to eat enough to support her and her lambs. Even though the ewe is not pregnant anymore, her abdominal wall still needs to support her heavy rumen and other abdominal organs. In some ewes the extent of the rupture can worsen after lambing, severely compromising her quality of life.
Additional images, and more information on prepubic tendon ruptures and abdominal wall hernias can be seen
https://rvz.emnuvens.com.br/rvz/article/view/39/25
https://www.semanticscholar.org/reader/ef122c36428ab64c96d85bfd3243f374389f8522
https://talk.newagtalk.com/forums/thread-view.asp?tid=610810&DisplayType=nested
https://visgar.vetmed.ufl.edu/en_ovirep/abdominal-hernia/abdominal-hernia.html
https://visgar.vetmed.ufl.edu/en_ovirep/ruptured-prepubic-tendon/ruptured-prepubic-tendon.html
By: Isabel Richards, EAPK Communications Committee
