Uterine torsion
Key words: uterus, torsion, bovine, accident, pregnancy
Uterine torsion is not uncommon in cows. It is seldom encountered in heifers and is also infrequent in Bos taurus var indicus cattle. The reasons for those findings are not clear but have been related to large, deep and expansive abdomens in affected breeds and parity. Uterine torsion is also more common in unfit dairy cows kept in barns than those at pasture; perhaps a consequence of poor abdominal muscle tone and weak limbs allowing sudden jerky movements. Not surprisingly, uterine torsion has also been related to poor uterine tone and hypocalcemia.
One only has to appreciate how the hind quarters of a cow are elevated above its thorax when it rises or lies down to imagine how the stability its pendulous uterus becomes precarious in that posture. The inherently poor stability the bovine uterus adds to this predisposition. Consider the attachment and flaccidity of the mesometrium in cattle. This allows one to easily retract and manipulate a non-pregnant bovine uterus during transrectal palpation. During pregnancy the mesometrium offers even less support as the pregnant uterus expands cranially, beyond the cranial margin of the mesometrium.
In twin pregnancies, the uterus is more evenly loaded and is a result, more stable. Not surprisingly, uterine torsion is comparatively rare in cows with twin pregnancies.
In twin pregnancies, the uterus is more evenly loaded and is a result, more stable. Not surprisingly, uterine torsion is comparatively rare in cows with twin pregnancies.
Uterine torsion occurs in all ruminants and even multiparous animals but is most common in cows and horses, especially cows. In horses, mesometrial support is far more substantial than it is in cattle. One only has to try to retract an equine uterus to appreciate that reality. Even during pregnancy, the equine uterus is more stable than a bovine uterus. Also, mares change from the lying to standing posture by raising their forequarters first, so the equine uterus seldom finds itself in a pendulous state. The cause of uterine torsion is different between the two species; in cattle, as explained, it is due to uterine instability during early parturition. In mares it appears to be related to mares rolling in pasture during mid to late gestation; perhaps as they shed their winter coats.
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In this entry, all descriptions of the direction of torsion are written as if one is looking at the cow, caudal-to-cranial. In that regard, anti-clockwise torsion is more common than vice versa. The reason for this is not obvious and the author's speculation will not add to the value of this entry. In the case discussed here, torsion was in a clockwise direction.
This illustration is found elsewhere in various manifestations on the Internet. However, the original image was drawn by Dr Ronald Trengrove circa 1971. Shortly before his death in 2014, Dr Trengrove gave the author permission to use and edit his veterinary drawings. font-weight: normal>
In rare cases, uterine torsion can occur during mid gestation but it is usually a condition associated with calving. Typically, a cow affected with uterine torsion will show cessation of calving but continuing signs of discomfort. The farmer notes the typical mucous discharge from the vulva (see figure 2) the presence of colostrum, and obvious signs of impending parturition. Then there is no further progress. After several hours of inactivity but persisting discomfort, a veterinarian is called.
If the fetus or its membranes have entered the vagina, there may be a degree of straining. On transrectal examination, a tight mesometrial ligament can be felt stretching across the caudal abdominal cavity. Torsion of the uterus may be palpable per rectum as a corkscrew to the left or right-hand side. On vaginal examination, torsion is usually detected, but in a few cases, the site of torsion is cranial to the cervix and vaginal torsion may be absent. If the cervix has dilated, fetal limbs may be in the vagina. Often however, uterine torsion occurs before the cervix has dilated completely. If torsion is not relieved, fetal death, putrefaction and toxemia will result.
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A plastic device named "Gyn-Stick", similar to the Cornell detorsion rod, is available from Jorgensen labs. It is made from rigid plastic and uses calving ropes in place of chains. Its use is shown in this commercial video.
The author was introduced to the Cammerer's detorsion fork as an undergraduate in 1972. It is shown in figure 5, a diagram by the author. The commercial product can be seen on this website, still commercially available. In the author's opinion it is preferable to Cornell-style instruments because large cuffs spread the torsion load on the limbs and the fork enlarges the radius of rotation compared to other detorsion instruments.
Figure 5: A Cammerer's* detorsion fork' often referred as a torsion fork. Size available: 624 x 1132px
Figure 6: After successful detorsion, the cervix of the cow was dilated manually over a period of 15 to 20 minutes prior to extraction and the calf. The obstetrics chains were moved distally from their original positions on the left and right proximal radius and ulna; they were placed on conventional traction sites, above each fetlock joint. As is usually the case, the chains were also thrown into a half hitch proximal to each pastern joint. Size available: 1409 x 1119px
Figure 7: Torsion was then used to rotate the calf by 110 to120 degrees into a dorso-left-ilial position to prevent hiplock; a normal part of mutation and traction in any assisted calving. Size available: 1600 x 1200px
Figure 8: The calf was dead in this case probably because torsion was protracted and severe. In one large study (Klaus-Halla, D. et al. 2018) 35 percent of calves were delivered live if the case was treated within 12 hours after the onset of calving and approximately 90% if treatment began within 6 hours. Size available: 942 x 1461px
In some cases the cervix has not yet dilated at the time of presentation or the uterus has twisted to such an extent as to preclude entry by the operator. In those cases, the cow must be rolled to relieve torsion. After torsion is relieved, it is possible to determine if the cervix and body of the uterus can be accessed to deliver the calf. Fortunately, in the majority of cases, the cervix will have dilated enough to permit per vagina mutation.
In the opinion of some, if cervical dilation is insufficient to allow per vagina delivery after rolling, one should wait for at least three hours for this to occur. However, the cervix may never dilate sufficiently in some cases and even if the cervix does dilate, a second visit to the farm will be required at extra cost; only to deliver a dead calf. In the author's opinion therefore, it is preferable to perform a Cesarean section immediately after rolling in those cases.
Even if the cervix is closed and it appears impossible to deliver the calf per vagina, the cow should be rolled to correct torsion. This will facilitate Cesarean section if it is required. In the event that a Cesarean is attempted before torsion is corrected, the uterus, once freed of the weight of the calf, may contract and rotate away from the surgeon. This makes the uterine wall difficult to suture.
A highly experienced colleague responded to this statement by saying that his standard approach to torsion is to perform a cesarean section immediately in all cases of torsion.
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The technique of "rolling" is shown in figure 9.
Figure 9: Correction of uterine torsion by rolling (Schaffers’* method). The uterus has twisted clockwise in this case. This is shown by the inner, circular red arrow “a”. An attempt is made to roll the cow in the same direction (large red arrow) as the uterus has twisted so that the cow twists around her own uterus. A plank is often used to facilitate this process with pressure applied to the cow's abdomen, just cranial to her udder. During rolling, pressure on the uterus helps to prevent rotation of the twisted uterine horn. Although the affected uterine does not rotate during rolling, it could be said that it rotates anticlockwise relative to the cow. In this case that would be in the direction shown by the circular green arrow “b”. If rolling successful, fetal fluids usually escape from the cow's vulva lips immediately after torsion is relieved. An attempt should then be made to mutate and extract the calf. Size available: 1200 x 894px
*The author has been unable to determine the exact origin of the eponym Cammerer Any assistance in that regard will be appreciated. Schaffer published on his plank modification for uterine torsion in 1946 (see references).
Selected references:
Frazer, G.S. 1996. Bovine uterine torsion: 164 hospital referral cases. Theriogenology. 46:739-758
Klaus-Halla, D. et al. 2018 In German. Translated: [Uterine torsion in cattle: Treatment, risk of injury for the cow and prognosis for the calf] Tierarztliche Praxis. 46:143-148
Lyons N et al. 2013. Clinical forum: Bovine uterine torsion. Livestock. 18: 18-24
Pascale, A. et al 2008. A study of 55 field cases of uterine torsion in dairy cattle. Can Vet J. 49:366–372
Roberts. S.J. Veterinary obstetrics and genital diseases (Theriogenology). Published by the author. Uterine torsion. pp 230-233
Roelofsen, J.M.P. 2018 Uterine Torsion in relation to blood calcium concentration in dairy cattle. Masters Thesis University of Utrecht.
Schaffer W. 1946. Schweizer Arch. Tierheilk 88: 44.
