Weighing up the risks

I have a small Jack Russell cross who weighs just under 7 kg. I have not had her spayed and during her last season she developed a false pregnancy. I was told to have her spayed because she is more at risk of developing a pyometra. Is this correct? I am not going to breed from her and her seasons are well controlled, but I am worried about incontinance and a few other things if I have her spayed.

Thank you,

S. Tasker, by email



Alison Logan, vet, advises...

To spay or not to spay – that is the question. And there is no simple answer because there is no disputing that it is the most involved of the routine surgical procedures, and your bitch will need a general anaesthetic. Equally, do remember that because spaying is so commonly performed it is also a procedure which your vet will be very used to doing.

I am not sure that having a false pregnancy will make your bitch more at risk of developing a pyometra. It is true to say, however, that with every season there is an increased risk of any bitch going on to have a womb infection. Pyometra is a very serious condition, developing a few days to a few weeks after a season. There are essentially two possible scenarios:

- closed pyometra: abdominal enlargement and pain, fever, lethargy, increased thirst, vomiting

- open pyometra: the owner may notice little more than an unpleasant discharge from the vulva

There are medical options for treating a bitch with a womb infection or pyometra. Spaying is, however, generally the main course of action, although the risks are obviously far higher than for a routine planned spay when the patient is fit and well and usually much younger so without any health concerns associated with ageing.

As vets we would therefore prefer to spay when a bitch is young and healthy. There is a risk of urinary incontinence which can usually be managed, although I have not encountered a case for some years now so there may be other factors which have changed. The often-quoted association with mammary tumours and a protective effect of early spaying is unclear and still under investigation. When I first qualified more than twenty years ago, I would be regularly finding mammary tumours when running my hands along the underside of bitches at routine visits, whereas I have certainly noticed that this has become a real rarity in recent years. Seeing a patient booked in for a mastectomy is noteworthy, not at all common.

Weight gain after spaying is another reason that puts owners off having their bitches spayed. In my view, it is far outweighed by the advantages of spaying, especially as it is simply a matter of appreciating that when a bitch is spayed her body slows down by as much as 20%. Cutting back on her ration, coupled with a switch to a food formulated for a neutered dog if feeding a commercially-prepared diet, should prevent weight gain. If it is a planned spay, then it is going to be best performed when the bitch is at her ideal bodyweight as it will be hard to shift weight after spaying. This is another reason to avoid being rushed into spaying by the development of a womb infection.

Then there is the matter of unplanned pregnancy. I assume this is what you mean by having good control of your bitch’s seasons. It is alarming how often accidents do happen…

The decision to have your bitch spayed is very much your own decision and does merit careful thought. I hope this has helped, and would urge you to discuss it further with your vet in order to come to a reasoned decision.