Ep 17 - Neutering Dogs in 2026: Why “One Size Fits All” Advice Is Starting to Disappear

For many but not all clinicians, the neutering conversation in dogs felt fairly straightforward.

Castrate the males. Spay the females. Usually around six months. Job done.

But the more evidence that comes out, the harder it’s becoming to justify blanket recommendations — especially in medium and large breed dogs.

And honestly, I think many vets have quietly felt this for quite a while.

In Episode 17 of the Chatty Vets Podcast, Charlotte and I discussed the growing evidence around neutering, orthopaedic disease, cancer risk, urinary incontinence, behaviour changes, dachshunds and IVDD… and why these conversations are becoming much more nuanced than they used to be.

The old advice: “Neuter everything at six months”

Historically, neutering advice was simple because it solved obvious problems:

• Prevent unwanted litters

• Reduce pyometra risk

• Eliminate testicular disease

• Reduce some hormone-driven conditions

• Potentially reduce mammary tumour risk

And many of those benefits are absolutely real.

But increasingly, studies are showing associations between early neutering and several important diseases — particularly in medium and large breed dogs.

That’s where the discussion gets more complicated.

Orthopaedic disease and skeletal maturity

One of the clearest shifts in recent years has been around orthopaedic disease.

There’s growing breed-specific evidence associating early neutering with increased risk of:

• Cranial cruciate ligament disease

• Hip dysplasia

• Elbow dysplasia

• Other developmental orthopaedic conditions

Charlotte highlighted that some studies suggest dogs with the least gonadal hormone exposure — in other words, those neutered earliest — may be at greatest risk.

Clinically, that fits what many of us feel we’re seeing.

We all see cruciates constantly. We all see young large breed dogs with orthopaedic disease. Whether hormones are the entire explanation is debatable, but the association is becoming difficult to ignore.

This is why many vets now discuss delaying neutering until skeletal maturity, particularly in medium, large and giant breeds:

• Often 12–18 months minimum

• Sometimes closer to 18–24 months in giant breeds

That’s a very different conversation from the old “book them in at six months”.

Male dogs: are we over-castrating?

This is probably one of the biggest philosophical shifts.

For decades, castration was often presented as a general health benefit for male dogs.

But when you actually look at the evidence, the reality is more balanced.

Entire male dogs are certainly more prone to:

• Benign prostatic hyperplasia (BPH)

• Prostatic infections

• Perineal hernias

• Anal adenomas

• Testicular tumours

But many of these conditions:

• occur later in life

• are manageable

• or are resolved by castration at the time anyway

Meanwhile, neutering may also be associated with:

• orthopaedic disease

• some cancers

• urinary issues

• and potentially increased anxiety-related behaviours in some dogs

So increasingly, the question becomes:

“Does this individual dog actually need to be castrated?”

Sometimes the answer is absolutely yes.

If a dog:

• humps excessively

• struggles socially

• is difficult around other dogs

• is escaping

• or owners simply cannot safely manage an entire male

…then castration may dramatically improve quality of life for everyone involved.

But we probably need to move away from the idea that neutering every male dog is automatically a universal health benefit.

Behaviour: testosterone isn’t always the villain

One thing Charlotte raised that I think is really important is behaviour.

We often think:

testosterone = bad behaviour

But testosterone also contributes to confidence.

And in anxious, nervous or insecure dogs, castration can sometimes worsen fear-based behaviours.

That doesn’t mean neutering is wrong.

It just means behaviour discussions should probably form part of the consultation rather than being treated as an afterthought.

Chemical castration can be really useful here because it gives owners a “trial run” before committing to irreversible surgery.

The cancer evidence is evolving

This is where the conversation becomes more difficult.

Several breed-specific studies — particularly involving Golden Retrievers and Rottweilers — have reported associations between neutering and increased rates of:

• lymphoma

• haemangiosarcoma

• mast cell tumours

• osteosarcoma

Charlotte mentioned studies suggesting neutered male Golden Retrievers developed lymphoma more commonly than intact males.

Similarly, some Rottweiler studies have reported markedly increased osteosarcoma risk associated with early neutering.

Now, this is important:

• these studies are often breed-specific

• some involve relatively small populations

• and we should be cautious about over-extrapolating the findings to every dog

But the signal keeps appearing often enough that it probably deserves serious discussion.

Mammary tumours: the old teaching is being questioned

Traditionally, we were taught:

• neuter before first season = huge reduction in mammary cancer risk

• after second season = protective effect largely lost

But much of that teaching came from older evidence with significant methodological weaknesses. Charlotte raised the possibility that neutering may not need to be that early to stop mammary neoplasia. Though, anecdotally, I feel like I have seen occasional cases of mammary tumours in dogs neutered at 5-6 years of age.

That doesn’t mean hormones don’t matter for mammary tumours — they almost certainly do.

But the exact magnitude of benefit from very early spaying may not be as clear-cut as many of us were originally taught.

This area still feels genuinely unresolved.

Dachshunds and IVDD

Another growing discussion is whether early neutering contributes to IVDD risk in Dachshunds.

The evidence here remains mixed.

Some studies suggest increased IVDD risk with early neutering, particularly before 12 months, while others show less clear associations.

At the moment, I don’t think the evidence is strong enough to make rigid neutering recommendations based purely on IVDD risk alone.

But it’s certainly becoming part of the conversation.

Urinary incontinence in large breed bitches

There’s good evidence that:

• neutered bitches have increased urinary incontinence risk

• neutering before six months increases that risk further

• larger breeds are particularly affected

Charlotte mentioned the 2019 RVC study looking at early-onset urinary incontinence in UK bitches, which is well worth reading.

And honestly, this is probably one of the strongest practical arguments against very early neutering in larger breed females.

So… what should we actually recommend?

I think the biggest takeaway is this:

There probably isn’t a universally correct answer anymore.

Instead, the conversation should include:

• breed

• size

• behaviour

• household setup

• orthopaedic risk

• cancer predisposition

• owner priorities

• and lifestyle

For many medium and large breed dogs, delaying neutering until maturity increasingly feels sensible.

For some male dogs, not castrating at all may genuinely be reasonable.

For others, neutering may absolutely still be the right decision.

The important thing is that we stop pretending this is a simple conversation.

Francisco Gomez on ophthalmology in general practice

We also had a brilliant chat with Francisco Gomez, an Advanced Practitioner in Veterinary Ophthalmology who has worked extensively in both referral and first-opinion practice in the UK and Spain.

He made a really good point that many vets “don’t like eyes” largely because ophthalmology often isn’t taught particularly well at university — and once something feels intimidating early on, it tends to stay intimidating.

One of the biggest clinical messages from the discussion was:

Don’t forget the Schirmer tear test.

Francisco highlighted several really useful practical points:

• Perform Schirmer tear tests before applying drops or fluorescein

• Always test both eyes

• Normal canine tear production is generally around 15 mm/min or higher

• Dry eye discharge is often mistaken for bacterial infection

• True bacterial conjunctivitis in dogs is actually relatively uncommon

He also explained that many “non-healing ulcers” are often cases where the underlying cause hasn’t been identified properly:

• dry eye

• ectopic cilia

• exposure keratitis

• entropion

• lagophthalmos in brachycephalics

• or neurogenic dry eye

…rather than simply “needing stronger antibiotics”.

One particularly interesting point was his discussion around ulcer sampling and antibiotic choice. Francisco argued that in some cases we probably overuse broad empirical antibiotic changes without asking why the ulcer developed in the first place.

He also discussed the difference between:

• distichia

• ectopic cilia

• and trichiasis

—which, if we’re being honest, many of us probably haven’t revised since vet school.

SPODS — Francisco’s ophthalmology teaching group

Francisco also runs a really interesting ophthalmology teaching group on Facebook called SPODS.

The group focuses on:

• short ophthalmology teaching videos

• practical clinical tips

• case discussions

• Schirmer tear test technique

• ulcer workups

• interpreting eye findings in practice

• and interactive ophthalmology CPD

  
  

Francisco also runs small-group online interactive CPD sessions where vets work through real ophthalmology cases together in a very relaxed environment.

Honestly, if eyes make you slightly nervous in practice, it sounds genuinely useful.

If you want the full discussion — including grape toxicity debates, euthanasia payment conversations, neutering controversies and Francisco’s ophthalmology teaching — Episode 17 is live now.

And yes… I suspect the neutering debate in the comments is only just getting started.