Uterine torsion (which is a term that means twisting on its axis) occurs when one horn of the uterus twists at the junction between the body and the horn and it involves the proximal end of the uterus or even the ovary. Think of it sort of like tying a twist tie on a bread bag.
Uterine torsion has been reported as a relatively uncommon complication of pregnancy in the cat, however, it may be more common than first thought, with case reports published in veterinary and breeder journals.
Uterine torsion typically happens in mid- to late gestation. It can occur in any age cat, whether they have previously had litters or not, although case reports seem to indicate an increased risk in queens that have already birthed a litter.
There is very little information in the veterinary literature regarding uterine torsion in cats. And, of course, the recommended treatment is ovariohysterectomy — spaying the female — which may not be the ideal solution for the cat breeder who would lose the breeding career of a valuable queen.
It is important to recognize this disorder quickly if it occurs in one of your queens. It can be life-threatening.
Cause Of A Twisted Uterus
There are many theories as to what causes uterine torsion although nobody knows for sure. Case reports seem to indicate an increased risk in queens that have multiple fetuses in one horn with none or a single fetus in the other.
Other possible risk factors may include:
- Increased activity of the queen
- Weakness of the uterine wall
- Movement of the fetuses
- Rough handling of the queen
There is no way to predict whether this complication will occur.
Signs Of Uterine Torsion
The most common initial clinical sign of a twisted uterus is a bloody discharge from the vulva. Other signs include:
- Abdominal Pain
- Distended Abdomen
- Bloody Vaginal Discharge
- Pale Mucous Membranes
- Generalized Weakness / Collapse
- Difficult labor that does not progress
Many of these signs are consistent with symptoms of shock.
Diagnosis is based on:
- Medical History
- Physical Examination
- Blood Tests (blood counts & serum chemistries}
- NOTE: If the cat has a twisted uterus, an enlarged uterus will be detected. Unfortunately, it may be difficult to differentiate a pyometra from a blood filled uterus from a torsed uterus with fetuses. This is a moot point since a queen with an enlarged uterine horn, and signs of shock needs to be taken immediately to surgery regardless.
It is often difficult to differentiate a twisted uterus from pyometra
unless kitten skeletons are clearly visible on the x-rays.
This is an emergency situation. The survival of the queen as well as the fetuses depend on how quickly the problem is diagnosed and treated. The queen should be taken immediately to a veterinarian. Many veterinarians may have never seen this disorder in a cat and therefore you need to make them aware of the possibility.
- Treatment for shock including IV fluids should be instituted immediately.
- Once uterine torsion is suspected, an immediate exploratory laparotomy should be performed.
- An ovariohysterectomy (spay).
The kittens in the uterine horn that is twisted are almost always dead. If only one horn is affected, kittens that are located in the horn of the uterus that is not torsed may be able to survive the anesthesia, continue to full-term and be delivered normally. If the kittens are already (or with 3 days) full-term, they should be delivered by c-section during the initial surgery for the uterine torsion.
The torsed uterine horn should NOT be untwisted during the surgery since the blood flow to the tissue has been cut off and toxins from the dying tissue can be released into the queen's bloodstream if the horn is untwisted.
A case report in a 1996 issue of The Cat Fancier's Journal written by Debra Mitchell detailed a queen with one twisted uterine horn at 4 weeks of gestation that had one kitten in the normal horn that survived anesthesia and was delivered normally and went on to become a CFA Grand Champion.
Saving The Queen's Reproductive Career
A valuable queen's reproductive capability may be saved if the twisted uterus is diagnosed quickly and your veterinarian is willing to consider other options than a complete ovariohysterectomy. This is where you need to have a good working relationship with your veterinarian. A queen with one normal uterine horn could conceive and carry future kittens to term. This would require that the affected uterine horn be removed and the normal horn be left intact.
Death Of The Queen
Since most queens are already showing signs of shock by the time a twisted uterus is diagnosed, death of the cat does occur in some of these cases.
Immediate detection of uterine torsion and professional care will greatly increase the queen's survival rate. The best thing you can do is make sure to look at your pregnant queens carefully multiple times daily. Examine the vulva, monitor appetites and activity levels. Any abnormalities should be taken very seriously.