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December 2010 Issue
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A New and Safer Way to Spay Your Puppy
Fewer complications result from removal of only the dogs ovaries.
Making a fresh look at the things we take for granted can be wonderfully enlightening. Sometimes, the little light bulb overhead begins to sizzle and sparkle, illuminating a new and better way of doing things. Consider this example: When some savvy veterinarians took a fresh look at performing spays, a surgery we’ve been doing the exact same way for decades, they came up with a revised technique that accomplishes all of the objectives of the spay surgery with fewer complications. How cool is that?
![]() No wonder female dogs are sore during recovery from conventional spay surgery removal of the ovaries and the uterus requires the veterinarian to physically manipulate and cut away quite a bit of tissue. Removal of the ovaries alone is faster and less traumatic, and the patients recover more quickly. |
Spay is the term used for neutering a female dog. As I was taught in veterinary school, the medical jargon for spaying is ovariohysterectomy (OVH). “Ovario” refers to ovaries, “hyster” refers to uterus, and “ectomy” means removal of. In other words, spaying the traditional way involves surgical removal of the uterus and both ovaries. The objectives of the spay surgery are to render the dog infertile, eliminate the mess and behavioral issues associated with a female dog in heat, and prevent diseases that may afflict the uterus and ovaries later in life.
Thanks to some innovative veterinarians, we now know that ovariectomy (OVE) – removal of just the ovaries, leaving the uterus in place – accomplishes these objectives just as effectively as does the OVH. And, here’s the icing on the cake: removal of the ovaries alone results in fewer complications when compared to removal of the ovaries and uterus combined.
Female canine anatomy
Here’s a simple short course in canine female reproductive anatomy and physiology that will help explain why leaving the uterus behind makes sense. The shape of the uterus resembles the capital letter “Y.” The body of the uterus is the stem and the two uterine horns represent the top bars of the “Y.” An ovary is connected to the free end of each uterine horn by a delicate structure called a fallopian tube (transports the egg from the ovary into the uterus).
While the uterus has only one purpose (housing developing fetuses), the ovaries are multitaskers. They are the source of eggs of course and, in conjunction with hormones released by the pituitary gland, ovarian hormones dictate when the female comes into heat and becomes receptive to the male, when she goes out of heat, when she ovulates, and when her uterus is amenable to relaxing and stretching to house developing fetuses.
After the ovaries (and the hormones they produce) have been removed from the body, the uterus remains inert. The dog no longer shows symptoms of heat, nor can she conceive. Additionally, any chance of developing ovarian cystic disease or cancer is eliminated.
Better outcome
What happens when we leave the uterus behind? Isn’t it subject to becoming diseased later in life? Actually, the incidence of uterine disease in dogs whose ovaries have been removed is exceptionally low. Pyometra (pus within the uterus), is the most common uterine disorder in unspayed dogs, and typically necessitates emergency surgery to remove the uterus.
Without the influence of progesterone, a hormone produced by the ovaries, pyometra does not naturally occur. The incidence of uterine cancer is extremely low in dogs (0.4 percent of all canine tumors) – hardly a worry, and studies have shown that the frequency of adult onset urinary incontinence (urine leakage) is the same whether or not the uterus is removed during the spay procedure.
If you are not already convinced that the “new spay is the better way,” consider the following complications that can be mitigated or avoided all together when the uterus remains unscathed:
- Compared to an OVH, an OVE requires less time in the operating room. This translates into decreased likelihood of anesthetic complications.
- Removal of the uterus requires that the surgeon perform more difficult ligations (tying off of large blood vessels and surrounding tissues with suture material before making cuts to release the organs from the body). A uterine body ligation that isn’t tied quite tightly enough can result in excessive bleeding into the abdominal cavity and may necessitate blood transfusions and/or a second surgery to stop the bleeding.
- The ureters (thin delicate tubes that transport urine from each kidney to the bladder) run adjacent to the body of the uterus. If a surgeon is not being extremely careful, it is possible to ligate and obstruct a ureter in the course of removing the uterus. This devastating complication requires a second corrective surgery; however, damage to the affected ureter and adjoining kidney may be irreversible.
- Removal of the uterus occasionally results in the development of a “stump granuloma” – a localized inflammatory process that develops within the small portion of uterus that is left behind. When this occurs a second “clean up surgery” is typically required.
- We know that the degree of post-operative patient discomfort correlates with the degree of surgical trauma. No question, of the two surgical options the OVH creates more trauma.
European veterinarians have been performing OVEs rather than OVHs for years. In fact, the bulk of the research supporting the benefits of leaving the uterus behind has been conducted in Europe.
Slowly, veterinarians in the United States are catching on, and some veterinary schools are now preferentially teaching OVE rather than OVH techniques to their students.
What should you do if you are planning to have your dog spayed? Talk with your veterinarian about this article. Perhaps OVE surgery is already his or her first choice. If not, perhaps your vet will be willing to take a fresh look at performing this old-fashioned surgery.
Nancy Kay, DVM, is a Diplomate of the American College of Veterinary Internal Medicine (ACVIM) and recipient of the American Animal Hospital Association 2009 Animal Welfare and Humane Ethics Award. She is also author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life, and a staff internist at VCA Animal Care Center in Rohnert Park, California.


Comments (9)
I think you have this all backwards! Just as in human females, you leave at least one ovary if at all possible and remove the uterus! Sure it is easier for the Vet to remove the ovaries, but as you state yourself, you are removing the multitasking organ and leaving the one that has only one purpose, and that is to carry fetuses.
The ovaries are needed to keep the rest of the endocrine system in balance (multitasking), not simply to create eggs for fertilization.
You now have left and organ that has no purpose, removed the ovaries that regulated the uterus and told it what to do. I agree totally with the above posted who stated, you have now left a female totally open to pyometra!!! Pyometra is a bacterial infection and not caused by the hormones, but by bacteria. The cervix is allowed to be relaxed and open after a female comes into season (which is when it is most likely for the bacteria to enter the uterus and allow pyometra to develop.
Posted by: jerrier | July 16, 2011 1:35 PM Report this comment
Dear Dr. Kay: Does this hold true for laproscopic surgery as well? Any comments on laproscopic versus conventional surgery for spay? Thank you.
Posted by: Jose M | March 16, 2011 6:20 AM Report this comment
My dog is having a canine vasectomy done this week as an alternative to full castration. From the research I have done, the pros definitely outweigh the cons in comparing the two procedures. I have also read that partial spays (as your article describes) and tubal ligation in females may indeed yield better [healthier] results than tradition spaying. I would love to know more of The Whole Dog Journal's take on alternative procedures to spay and neuter. I pasted a couple of interesting links below: http://www.naiaonline.org/pdfs/LongTermHealthEffectsOfSpayNeuterInDogs.pdf http://www.petmd.com/blogs/fullyvetted/2010/april/ligations_vasectomies
Posted by: Bob | February 15, 2011 12:52 PM Report this comment
Dr. Nancy - It's been ten years since we had a puppy and we will be getting a male. Is there any new thinking about neutering? Just wondering about a vasectomy vs.a typical neutering. Thanks...
Posted by: BARB G | January 2, 2011 9:52 AM Report this comment
to Nancy K; I read the article and since "I" myself had a dog that was spayed (ovaries also) that had stump pyometra (the spay type left a small uterine stump) and I know of several other such cases also, pyometra can indeed occur without ovaries
ADDITIONALLY if the dog ever had a heat cycle before the Ovary removal surgery only is done, she will already have had hormone changes to the uterus
Personally if you are removing any body parts (ie ovaries only surgery or the uterus only surgery a few vets are doing) then I say take it all out and avoid all health risks.
Posted by: rottlady | December 20, 2010 2:38 PM Report this comment
This is in response to Rottlady's comment. I encourage you to have another look at the article that explains how pyometra occurs- can only happen if the dog is under the influence of progesterone- a hormone produced by the ovaries. No ovaries means no progesterone which means no pyometra. The only weird way a pyometra could occur is if the dog received some sort of progesterone compound. For example, some women take progesterone to help prevent miscarriage- I suppose if a dog accidentally ingested this medication, a pyometra could occur. Chances of this are so very slim that I hardly view it to be a valid argument. I hope this provides some clarification.
Best wishes,
Dr. Nancy Kay
Posted by: NANCY K | December 19, 2010 12:47 PM Report this comment
while this surgery is safer at time of surgery, it can put the dog at risk later in life. leaving a uterus means leaving the risk for pyometra there. Older females are at a very high risk for pyometra (uterus infection) and emergency pyometra surgeries are both costly and very high risk
No thanks. When I spay it will be a full spay (uterus and ovaries) to both stop heat cycles/pregnancy risk AND prevent pyometra
Having done 2 pyo spays in the past I have no wish to repeat the process ever again
Posted by: rottlady | December 17, 2010 11:06 AM Report this comment
You read the WDJ?
Posted by: JOAN H | December 7, 2010 9:53 AM Report this comment
I prefer 100% natural dogs.
Posted by: Sandra S | November 29, 2010 6:49 PM Report this comment