To Spay or Not to Spay? That Is the Question

I just cannot make up my mind.

I have always had girls. Mostly because, growing up, we had Max, a chocolate brown miniature poodle with a very annoying habit of proudly displaying his ‘lipstick’ most evenings.

Girls have wonderful soft, lipstick-free tummies and, at least in my experience, are slightly less inclined to disappear over the horizon with selective hearing.

So it has always been girls.

The first was more happy accident than conscious decision. Ellie was a rescue puppy from the RSPCA and I loved her from the get-go.

But after Ellie, it became deliberate.

Jazz, Pepsi and Boodle followed and every one of them was spayed without hesitation.

That was what responsible dog owners did.

Our vet advised us to wait until after their first season, so we waited until after their first season. Then we booked the appointment, handed over the dog and collected her later wearing a slightly tragic expression and usually some form of lampshade.

I never really questioned it.

Why would I?

Pepsi and Boodle are still very much with us and, touch wood, both are remarkably healthy. Ellie lived until she was 17 and apart from a grass allergy and the general indignities of becoming a very old lady, she had few health problems at all.

Jazz was different.

At around 12 she ruptured the ligament in one of her back legs and needed surgery. She also struggled with her weight as she got older. Then came the incontinence.

Whenever Jazzy properly relaxed, perhaps curled up beside me for a cuddle or deeply asleep, she could suddenly empty a surprisingly large amount of urine without apparently knowing that she had done it.

This eventually resulted in one of the less dignified episodes of our life together: me following Jazz around the garden armed with a ladle because the vet needed a urine sample.

Jazz, quite reasonably, wanted some privacy.

Every time the ladle appeared underneath her, she stopped weeing, glared at me and moved somewhere else. We eventually managed it, but despite tests our vet couldn't find an obvious cause.

At the time, these were simply things that happened to my lovely old dog.

It was only much later that I started wondering whether any of them might have been influenced by a decision I had made for her years before.

Then along came Mouse

If I had followed exactly the same rule I had followed with every other dog, Mouse would have been spayed after her first season.

She wasn't. I honestly can't tell you why other than something in me kept saying, not yet.

My vet recommended that I have her spayed and there are perfectly sound reasons why vets recommend it. But this time I wanted more than a default answer. I wanted to understand what we gained by removing her ovaries and, equally importantly, what we might lose.

I have started to wonder why such a major, irreversible operation had always felt so routine.

So Mouse stayed intact.

She has now sailed through three seasons with remarkably little drama and I still haven't reached the point where taking her in to be ‘done’ feels right.

And then I started reading - (apologies this is the boring bit)

Is one season enough before we remove these vital hormones??

In October 2024, researchers Rachel Moxon, Gary C. W. England, Richard Payne, Sandra A. Corr and Sarah L. Freeman published Effect of neutering timing in relation to puberty on health in the female dog: a scoping review.

It looked at research concerning neutering across five areas of female dog health: bone and joint issues, cancers, obesity, urogenital disease and allergies. The thing that surprised me most wasn't what the researchers discovered. It was how much we don't know.

Most of the research uses age instead of development. That matters because a six-month-old Chihuahua and a six-month-old Great Dane are not at remotely the same stage of physical development. Even Mouse, who is a toy breed is having late growth spurts as we approach her 2nd birthday.

The conclusion they reached - we just don't know if neutering before or after a dog has fully grown has any implications on long-term dog health.

It means the neat answer I thought we had for years isn't actually very neat at all. Bugger.

What about Jazz?

Six studies in the review reported associations between younger neutering and developmental orthopaedic problems including cruciate ligament rupture and hip dysplasia.

That made my ears prick up because of Jazz.

I know and accept that this doesn't prove that spaying caused her ligament to rupture. These diseases have many influences, including breed, bodyweight, genetics and plain old bad luck. But it was enough to make me wonder whether the decision deserved a little more thought than I had given it at the time.

Her weight is more straight forward. Neutering itself is recognised as a risk factor for obesity, Although she was also an avid and competent 'bin raider' who could smell chicken from 100 metres - so maybe it's not just down to neutering.

Her incontinence is perhaps the bit that makes me wonder most. A large UK study found that spayed bitches had around three times the odds of urinary incontinence compared with entire bitches.

Of course, leaving a girl entire isn't risk-free either

This is the bit that matters. There are very good reasons to spay.

There is no possibility of an accidental litter. Diseases of the ovaries and uterus are removed or reduced. And then there is pyometra, a horrible, potentially life-threatening infection of the uterus.

One frequently cited Swedish study describes pyometra as affecting almost 25% of unspayed female dogs before the age of ten, although risk varies considerably between breeds.

Twenty-five per cent is not a number I can casually wave away because Mouse looks adorable in season pants. In fact, it's terrifying!

Spaying is also traditionally recommended to reduce mammary tumour risk. There is evidence suggesting a protective effect against these cancers when a girl is spayed. Even here, the evidence isn't completely clear. Spaying may reduce the risk of mammary tumours, but we still don't know exactly how much difference the timing makes.

So there are risks on both sides.

And perhaps that is the point.

Maybe the question has changed

Veterinary guidance is changing too.

In 2026 the British Veterinary Association and British Small Animal Veterinary Association updated their advice, moving explicitly away from a one-size-fits-all approach.

They still recommend spaying most female dogs.

But they also recommend considering the individual dog's breed, age, lifestyle and health, and generally delaying neutering until physical maturity, which may fall somewhere between 12 and 23 months depending on breed.

That feels very different from the conversation I remember having years ago.

Not when are you getting her done? But is spaying right for this particular dog, and if it is, when is the right time? I much prefer that question.

Maybe my own hormones have something to do with the way I feel about it now. Having had a radical hysterectomy and losing my own hormones. I understand first hand that they are not merely decorative accessories to be thrown away without consideration. I am perhaps more reluctant to remove Mouse's without a very good reason.

And yes, there is guilt wrapped up in this too.

I look back at Jazz and wonder whether anything might have been different.

I'll never know. I certainly don't think I knowingly harmed her. I made the decision that responsible owners were advised to make at the time, just as millions of other people did.

But Mouse has made me stop treating that decision as automatic.

Perhaps I will have her spayed eventually.

The risk of pyometra may become the thing that tips the scales. Her health may change. Better research may emerge. My vet and I may eventually decide that the balance of risk has shifted.

Or perhaps she will remain intact. I genuinely don't know. That, rather surprisingly, is where all my reading has left me.

Not anti-spay. Not pro-spay. Just much less comfortable with automatic spay.

For Mouse, right now, the answer is simply: Not yet.