I have heard that some vets take out the ovaries and the uterus, but others only take the ovaries. And that there are even some vets who are now using keyhole surgery to do this, but I guess there are very few vets with the equipment. What are the benefits of using this method? Can you be referred to a specialist?
I thought one of the benefits of neutering was the avoidance of pyometra - but if the uterus is left behind, could that still get infected, or does the lack of ovulation remove the risk?
Which of the methods is the least likely to result in incontinence?
And that age old question - when do you do the operation? After the first season, after the second? Earlier?
Paula Thompson, Cheshire
Edward Davies, Veterinary Surgeon, Cheshire Pet, says...
Hi Paula,
Here at Cheshire Pet we are regularly using keyhole surgery (or laparoscopy) to spay bitches. The main advantages are a significant decrease in pain with smaller incisions and a considerably quicker recovery time.
Postoperative recovery is so quick that often owners can’t tell their pets have had an operation; in fact, I actually did an exploratory procedure on my own dog, Henny, for a suspicious lump and my wife didn’t realise I had done anything, as Henny showed no signs at all.
We aim for the pets to leave the surgery as they came in – bright and alert and looking well – and we feel that the recovery period from laparoscopic spay is generally far faster than the traditional method of spaying – and a lot less painful.
I think the benefits of this technique will grow and I believe that perhaps in the not too distant future this technique will become the norm and will replace the standard spay procedure to a large extent. Bear in mind that this has only really been available in the UK for the last three to four years and at present it is only performed by very few practices, as the investment in training and equipment is significant. We feel really privileged to be able to offer this at Cheshire Pet.
Routinely only an ovariectomy is performed when a spay is done laparoscopically. (An ovariectomy is the removal of just the ovaries, not the uterus and the ovaries.) The uterus can be removed as well but it has been shown that this is unnecessary and of no benefit. Removing the uterus seems to be done as a historical technique in the UK rather than for clinical reasons. In most European countries ovariectomy has been performed for years, even using the traditional spay technique. It has been very well recognised and documented that once the ovaries have been removed then removing the uterus is of no value because the prolonged progesterone hormone production from the ovary is the drive behind the cause of pyometra. Once the ovaries are removed then that drive has gone and the risk of pyometra has gone.
I do not think the incidence of urinary incontinence is any different between laparoscopic spaying and traditional spaying. We would tend to suggest that if the dog is small i.e. less than 10-15kg then spaying before the first season is absolutely fine; however, in larger dogs spaying them between the first and second season seems to be preferable. This as we know avoids the risk of pyometra and can significantly decrease the risk of mammary tumours. The surgery – as with any spay – is best performed two to three months after the last season or in small dogs before the first season is anticipated.
Dear Paula,
Thank you for your letter, you have raised some excellent questions that are particularly topical at the moment given the increasing availability of key-hole procedures in veterinary surgery. I will try to address each of your questions in turn but unfortunately, and somewhat surprisingly, the veterinary profession does not have definitive evidence based answers for all of them!
Does the uterus have to be removed as well as the ovaries?
Historically, neutering or a 'spay' operation for a bitch has involved removal of both ovaries and the uterus to the level of the cervix (called an ovariohysterectomy or OVH) via an open approach (the surgeon makes a hole large enough to use their hands and fingers). Ovariectomy (OVE) is an alternative technique that involves removal of both ovaries whilst leaving the uterus in position and can be performed open or using a key-hole technique.
Ovariectomy has been the preferred technique in mainland Europe for many years because it can be performed through slightly smaller incisions, achieves the same overall effect as a 'traditional' spay, minimises the surgical trauma from neutering (by leaving the uterus in place) and does not increase the risk of urinary incontinence or pyometra compared to ovariohysterectomy. The uterus is only left in position if it appears normal during the procedure.
In theory, leaving the uterus in position could allow a uterine tumour to form in later life. In reality, uterine tumours are very rare in dogs and most are cured by removal of the uterus in the unlikely event that this becomes necessary.
What are the potential benefits of a key-hole spay?
Laparoscopic (key-hole) ovariectomy results in less tissue trauma than an open approach because the operation is carried out from within the abdomen which reduces the requirement to pull on the ovaries or uterus. In Humans, laparoscopic surgery has been shown to reduce pain, promote faster recovery and reduce hospital stay times. Accurate and objective pain assessment in veterinary patients is very difficult and whilst some studies have suggested that dogs spayed via laparoscopy are less painful than those operated via a conventional open approach, others have not been able to demonstrate a significant difference. Most vets who perform key-hole spays regularly do feel that the patients recover very quickly and suffer low levels of discomfort.
Humans obviously prefer to undergo operations that involve smaller scars, and many prefer the same for their dogs. Laparoscopic ovariectomy is usually performed by two or three incisions between 5-10mm long. In the unlikely event of a breakdown of an incision following laparoscopy, the small size of the 'hole' should minimise the risk of any vital structures becoming trapped. Many experienced veterinary surgeons are able to perform open spays through relatively small incisions but most are likely to be at least three to five centimetres long. Limiting any one laparoscopic wound to approximately 10 millimetres results in most surgeons allowing off-lead exercise sooner than they perhaps would following conventional open spay surgery.
Overall, key-hole spay surgery has a number of attractive qualities that can benefit veterinary patients, namely that of reduced tissue damage, excellent visualisation for the surgeon, and smaller wounds requiring shorter periods of postoperative rest. However, conventional spay surgery carried out by an experienced surgeon using an open technique usually carries a similarly low risk of complications and most dogs recover relatively quickly.
When should I spay my bitch?
Your last question involved the age-old debate of when is the best time to spay a bitch regardless of the technique used. The two main concerns are the possibility of increased risk of urinary incontinence after a spay but also minimising the risk from development of mammary tumours. Many of the actual numbers often quoted on this subject are not very scientific as they were based on reports written before veterinary surgeons appreciated the necessity for robust statistical analysis.
It is likely that the risk of development of mammary tumours significantly increases after the first season and then continues to rise slightly with each subsequent season thereafter for at least the first few years. Therefore, in order to minimise the risk from development of mammary tumours, bitches should be spayed before the first season, but there is also likely to be some benefit from spaying after later seasons until at some point, presumably during middle age, the benefit regarding mammary tumour development becomes minimal.
The risk of urinary incontinence is present following any neutering procedure, and unfortunately some bitches will become incontinent whether they are spayed or not. Investigations suggest that there may be some benefit from waiting for the urogenital tract to reach sexual maturity before spaying, to reduce the risk of developing incontinence, and therefore concerned owners may choose to wait until after the first or second season. It is also clear that urinary incontinence is the result of a complex interaction of many factors and therefore it cannot be simply attributed to an effect of sexual maturity alone.
There are some breeds with a particular predisposition for development of incontinence and therefore consideration should be given to spaying after the first or second season, or perhaps not spaying them at all. On the other hand, those breeds with a low incidence of urinary incontinence can be considered for early neutering, and this offers the maximal potential benefit in terms of mammary tumour development in later life and also of avoiding unwanted pregnancy.
Overall, when considering the issue of the timing of a spay surgery, your vet will be the best person to help you weigh up the factors relevant to your own dog. In many cases, neutering after the first season may represent a balanced compromise.
Chris Shales MA VetMB CertSAS DipECVS MRCVS
European Specialist in Small Animal Surgery
Willows Veterinary Centre & Referral Service
Highlands Road
Shirley
Solihull
West Midlands
B90 4NH
WWW. Willows.uk.net
Tel: 0121 712 7070
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