Ovariectomy (spey) with Fourlimb Marclamp - part II
Updated: Oct 19
Sponsored by Fourlimb sealing device, the device I use in this procedure, as per the videos.
Thanks Fourlimb for the partnership. It allows me to continue my teaching of Veterinarians.
This Webpage is Part II of an educational series that discusses desexing. This page focuses on discussing the difference between ovariectomy (just taking the ovaries) and ovariohysterectomy (taking the ovaries and most of the uterus).
Firstly, is a short video for those who are interested in the Fourlimb Marclamp for ovariectomy.
Part I on this desexing series, discusses the procedure of Ovary-Sparing Hysterectomy and can be found here; https://www.drabbietipler.com/post/ovary-sparing-hysterectomy
The Marclamp can be purchased here
VIDEO: QUICK Spey using the Marclamp.
Filmed at VSS Jindalee
Ovariectomy vs Ovariohysterectomy: Do We Really Need to Remove the entire uterus?
By Dr Abbie Tipler, Specialist Small Animal Surgeon
For decades, ovariohysterectomy (OHE) has been taught and performed as the standard method of surgical desexing of female dogs in many countries. But if the ovaries are being removed, is there actually a benefit to removing a normal uterus as well?
According to the 2024 World Small Animal Veterinary Association (WSAVA) Guidelines for the Control of Reproduction in Dogs and Cats, the answer is generally no.
When loss of gonadal hormones is desired and there is no uterine pathology or pregnancy, WSAVA recommends ovariectomy (OVE/OE) as the preferred surgical procedure for routine sterilisation of female dogs. The guideline is also published in the Journal of Small Animal Practice.
That recommendation is supported by decades of literature comparing ovariectomy with ovariohysterectomy.
Important context: This discussion addresses which operation to perform once gonadectomy has been selected. Whether an individual dog should undergo gonadectomy at all, and at what age, is a separate question, discussed within my other educational blog posts. Current WSAVA guidance recommends an individualised approach considering breed, sex, age, health, lifestyle and purpose rather than routine gonadectomy of every dog.
What is the difference between OVE and OHE?
An ovariectomy (OVE) removes both ovaries but leaves the uterus in situ.
An ovariohysterectomy (OHE) removes both ovaries and the entire uterus.
Both procedures remove the gonads. Therefore, both eliminate ovarian hormone production, prevent future oestrous cycles and render the dog infertile.
Does removing a healthy uterus provide an additional benefit once both ovaries have been completely removed?
For routine gonadectomy of a healthy female dog, the evidence does not demonstrate such a benefit — and OVE has several surgical advantages.
But doesn't leaving the uterus cause pyometra?
This is probably the most common reason given for performing an OHE instead of an OVE.
However, it misunderstands the pathophysiology of canine pyometra.
The development of cystic endometrial hyperplasia (CEH) – pyometra complex is strongly dependent upon hormonal stimulation of the uterus, particularly progesterone.
Remove both ovaries and the normal ovarian source of progesterone is removed.
The 2024 WSAVA guideline addresses this specifically: CEH–pyometra will not occur in the absence of residual ovarian tissue or an exogenous source of progesterone.
This is also supported by long-term clinical data. Okkens et al. followed dogs for 8–11 years after OVE or OHE. Complete follow-up data were available for 69 OVE and 66 OHE dogs, with no indication that endometritis had developed in the OVE group.
What about uterine cancer?
Technically, removing the uterus eliminates the possibility of subsequently developing a primary tumour in that organ.
But that needs to be considered in context.
The 2024 WSAVA guidelines note that the incidence of uterine tumours in dogs is low and many are benign. The authors also report that, to their knowledge, uterine neoplasia has not been reported in a dog or cat undergoing OVE alone before two years of age, although the incidence following OVE performed after two years of age remains unknown.
So while OHE undoubtedly removes the future possibility of uterine neoplasia, the available evidence does not establish prophylactic removal of a normal uterus as a meaningful health advantage sufficient to justify routine OHE over OVE.
If uterine pathology is present, of course, the situation is different.
What about urinary incontinence?
Post-gonadectomy urethral sphincter mechanism incompetence is an important potential consequence of desexing female dogs.
But removing the uterus in addition to the ovaries does not appear to protect against it.
Is ovariectomy actually a simpler operation?
There are several potential advantages.
a smaller incision and therefore potentially less pain;
shorter surgical time;
fewer potential sites of haemorrhage;
less opportunity for inadvertent ureteral ligation; and
easier access to the ovarian pedicles.
This is one of the reasons WSAVA now recommends OVE as the preferred procedure when gonadectomy is indicated in a female dog without uterine pathology or pregnancy.
A prospective randomised clinical trial by Peeters & Kirpensteijn compared OVE and OHE in 40 healthy dogs. OHE required significantly longer relative skin and fascial incisions, while the study did not demonstrate significant differences in postoperative pain or wound scores.
It is therefore reasonable to say that OVE involves less surgical dissection, but it would be an overstatement to claim that every open OVE has been proven to cause significantly less postoperative pain than every OHE.
An interesting question: are we actually performing an OHE?
There is another anatomical point raised by the WSAVA guidelines that is particularly relevant to veterinarians.
Many procedures traditionally described as an “ovariohysterectomy” involve ligation and transection at the level of the uterine body. But that doesn't actually remove the entire uterus. Some distal uterine tissue remains. WSAVA therefore describes this procedure more accurately as a subtotal ovariohysterectomy (SOHE). A true OHE involves removing the entire uterus, including the uterine body, with transection through or distal to the cervix.
This raises an interesting question.
If we are comfortable leaving a small amount of normal uterus behind during a traditional “OHE”, why is leaving the remainder of a normal, hormonally inactive uterus considered problematic?
There is also a potential downside to creating a uterine stump. WSAVA notes that retained uterine tissue following standard OHE provides the potential for uterine stump granuloma, while CEH–pyometra can occur if an ovarian remnant is present or the animal is subsequently exposed to exogenous progesterone.
For these reasons, the WSAVA guideline actually advises against standard OHE.
What about laparoscopic desexing?
The rationale becomes even clearer with minimally invasive surgery.
If removal of gonadal hormones is desired, most laparoscopic sterilisation procedures are performed as ovariectomies because removal of the uterus is not required to achieve sterilisation.
The ovaries can be visualised, their vascular pedicles sealed and divided, and the ovaries removed through small laparoscopic ports without extending the operation caudally to dissect the uterine body and cervix.
When should the uterus be removed?
If uterine pathology is identified or suspected, removal of the uterus may absolutely be appropriate.
Examples include pyometra, uterine neoplasia, uterine trauma, significant congenital or acquired uterine abnormality, and other reproductive tract disease in which hysterectomy is therapeutically indicated.
So, is ovariectomy really enough?
Yes.
If gonadectomy has been selected as the appropriate reproductive-control option for a healthy female dog, complete bilateral ovariectomy:
✓ Prevents pregnancy
✓ Prevents future oestrous cycles
✓ Removes the normal ovarian hormonal stimulus required for CEH–pyometra
✓ Does not appear to increase long-term urogenital complications compared with OHE
✓ Does not appear to increase the risk of post-gonadectomy urinary incontinence compared with OHE
✓ Requires a smaller incision
✓ Involves less reproductive tract dissection
✓ Has fewer potential sites for haemorrhage
✓ Reduces the opportunity for inadvertent ureteral ligation
✓ Is generally quicker
And, importantly, it is the procedure currently preferred by the 2024 WSAVA reproduction guidelines when gonadectomy is desired and the uterus is healthy.
The take-home message
For routine gonadectomy of a healthy female dog, there is no evidence-based requirement to remove a normal uterus.
References
Romagnoli S, Krekeler N, de Cramer K, Kutzler M, McCarthy R, Schaefer-Somi S. WSAVA guidelines for the control of reproduction in dogs and cats. Journal of Small Animal Practice. 2024;65(7):424–559. doi:10.1111/jsap.13724. Read the WSAVA Reproduction Guidelines
Okkens AC, Kooistra HS, Nickel RF. Comparison of long-term effects of ovariectomy versus ovariohysterectomy in bitches. Journal of Reproduction and Fertility Supplement. 1997;51:227–231. Okkens et al. on PubMed
Van Goethem B, Schaefers-Okkens A, Kirpensteijn J. Making a rational choice between ovariectomy and ovariohysterectomy in the dog: a discussion of the benefits of either technique. Veterinary Surgery. 2006;35(2):136–143. doi:10.1111/j.1532-950X.2006.00124.x.
DeTora M, McCarthy RJ. Ovariohysterectomy versus ovariectomy for elective sterilization of female dogs and cats: is removal of the uterus necessary? Journal of the American Veterinary Medical Association. 2011;239(11):1409–1412. doi:10.2460/javma.239.11.1409.
Peeters ME, Kirpensteijn J. Comparison of surgical variables and short-term postoperative complications in healthy dogs undergoing ovariohysterectomy or ovariectomy. Journal of the American Veterinary Medical Association. 2011;238(2):189–194. doi:10.2460/javma.238.2.189. Peeters & Kirpensteijn on PubMed
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