You're Once....Twice....Three (?) Times a Lady!

Working in a high volume spay/neuter clinic has its advantages.  Not only do I get to refine my skill so that my patients are under anesthesia for the shortest possible time and my incisions are only as large as necessary, I also get to see the weird reproductive anomalies more frequently than my colleagues.  Two weeks ago, I got to see a rare reproductive abnormality and it was fascinating!  Ever heard of uterus didelphys?  Why have one uterus and vagina when you could have two? 


My surgery day was going quite normal up until they placed that large red puppy on my table.  The pup, a 12 week old mixed breed, was normal on her preoperative physical exam and it was obvious that she would be a large dog in a few months.  She bowed her head and wagged her tail each time someone spoke to her.  She was adopted from a kill shelter and would be traveling to a family in the northern states by way of a collaboration of rescue organizations that transports these dogs many miles in order to save their lives.  Her gentle and attentive nature will make her an excellent pet.  Fortunately, she is required to be spayed prior to going on her long journey to her new home. 

The technician prepared her and opened my surgical pack.  I incised the skin, subcutaneous tissues, and parted the linea in order to open the abdomen for the surgery and reached in with my finger.  Fortunate to have done many of these surgeries, I can identify the uterus by the feel of the long smooth muscular organ and know exactly where to find it.  I hooked the right uterine horn with my finger and gently pulled it out of the opening in the belly.  I followed the uterine horn up to the right ovary, broke the ligament, ligated the vessels and severed the ovary from its attachments.  Then I followed the uterine horn back toward lower half of dog and found something missing.

Dogs and cats have a Y shaped (bicornuate) uterus.  The ovaries are attached at the top of each arm of the Y.  The arms of the Y are called the uterine horns.  The uterine horns house the babies during pregnancy.  Each horn opens into the base of the Y called the uterine body.  At the bottom of the base of the Y is the cervix which leads into the vagina.  To view a picture of an intact pregnant uterus, see the picture in my blog about double pregnancy, Reproductive Oddities. 

My normal routine is to free one ovary and uterine horn and follow it down the uterine body.  Here I can easily locate the second horn and follow it up to the second ovary.  However in this dog, there was no second uterine horn.  I could feel the cervix at the base of this uterus leading into the vagina.  So I amputated the uterus, checked for bleeding and allowed the vagina to return to its proper position. I assumed that the left uterine horn had simply not formed during development.  I decided to go looking for the left ovary since it could have possibly developed despite the lack of the uterine horn. 

I elongated my initial incision and began snooping around the left kidney.  Sure enough, there it was!  But what was this thing attached to it?  It sure looked like a uterine horn.   So I ligated the vessels, removed the ovary, and began to follow the uterus again toward the caudal end of the dog.  To my surprise, the uterus led me to a vagina.  But this vagina did not have my ligature around it nor had it been cut.  Confounded, I decided to look for the first vagina again.  I felt the need to prove to myself I was not imagining the first vagina.  I lifted up the urinary bladder and saw that the two vaginae rested beside each other as separate entities extending into the pelvic canal, where they could be seen no more. 

Obviously, there was much excitement in the surgery room.  Everyone had to be shown this rare find and, of course, pictures had to be taken......for the blog.

I finished removing the second uterus and sutured the dog's abdomen back together.  And then there was something I just had to do.  Can you guess?

I had to open this dogs vulva and take a look!  Sure enough, two very distinct vaginae were visible.  Sadly, there was no way to take a proper picture for your observation with the equipment I was using (a cellphone camera). 

Unsure what to call this condition, I was inspired to do a little research.  The name of congenital abnormality is uterus didelphys.  It is a rare condition caused by the failure of two embryonic structures, the mullerian ducts, to fuse during development.  Fusion results in the formation of one structure, the uterine body.  Without the formation of the uterine body, the ducts develop on to form individual cervices and vaginae.    The common name for uterus didelphys is double uterus.  I was unable to find much information specific to dogs in my research, so I am unable to inform you exactly how frequent this malformation occurs and if there are effects on the fertility and birthing process of affected dogs. 

Thank goodness I went looking for that second ovary.  Imagine my chagrin had I assumed that the left side of the reproductive tract had simply not developed and sewn up this dog's abdomen....only to have her deliver puppies several months later through her second reproductive tract.  I would have definitely had some explaining to do.  I sure hope there wasn't a third one hiding out in there!