Should you neuter your dog? If you’re looking for the signs your dog needs to be neutered, I’m afraid the answer isn’t a black and white yes or no. There’s a lot to consider before making this irreversible decision.
Vets have routinely recommended neutering from around 6 months of age for decades, but is it the right course of action for your dog?
In this blog, I’ll walk you through the pros and cons and share my experience as a dog trainer and walker who’s had decades of exposure to a range of dogs and behaviour struggles. But please note, this is anecdotal evidence and not a substitute for professional personalised advice for your dog – although I will share some science with you too.
Often in my encounters, it’s owners of male dogs who hope that neutering their dog will be a magic solution to what is sometimes quite normal (yet frustrating) adolescent dog behaviour.
But neutering your dog during the paediatric phase in their life isn’t a cut and dry decision.
Like everything with dogs, it’s nuanced. You have to look at the why beneath your dog’s behaviour before deciding whether neutering will have a positive or negative influence on your dog.
What does the science say?
There are many studies that have been undertaken on the influence of neutering in both male and female dogs that look at the impacts on both health and behaviour.
But it’s important to say that you can lead your own search here and find research to back up your own biases or hopes.
Here are some studies that contradict each other for reference – we’ll look at why these contraindications may occur next.
There are studies that evidence neutering helps to reduce aggression, emotional stability, and health issues.
There are also studies that evidence neutering as being linked to an increase aggression, guarding, fear and anxiety, and health issues.
Why the conflict?
I suspect that these studies can appear to contradict one another because there are so many influences on a dog’s behaviour. Hormones are just one part of the picture – we have to also consider genetics, lifestyle, training and learned experience to truly understand the sway on behaviour and health.
I will explore specific reasons you may be considering neutering your dog further down in this blog. But first, let’s talk about hormones and the role they play in your dog’s development.
Hormonal behaviour in dogs during puberty
During adolescence, a dog’s hormones are changing – and those changes can bring about frustrating and difficult behaviours (think of human teenagers), but they also play an important part in a dog’s development.
Your dog’s brain and body are going through a lot of changes during puberty, which is why you might see behaviours like:
- Increased reactivity/aggression (important to identify if this is true aggression or fear based)
- Increased nerves, fear or anxiety (in more than one environment)
- Reduced recall or ability to listen (increased interest and confidence in their environment)
- Increased sexual behaviour (like humping, excessive sniffing or roaming)
- Increased marking/scenting (different to genuine toileting)
- Reduced ability to control impulses (click here for help with impulse control training)
The chemicals produced during puberty and beyond for intact dogs all have an effect on your dog’s physical and emotional development.
Testosterone:
This hormone is primarily produced by the testes in male dogs and plays a crucial role in the development of muscle mass, bone, joint, and cartilage development – as well as the growth of reproductive organs. Testosterone can also influence behaviours related to mating, fear and aggression.
Oestrogen:
Oestrogen is produced primarily by the ovaries in female dogs and is responsible for the development of secondary sexual characteristics such as the widening of hips and the growth of mammary glands. It also assists with bone, joint, and cartilage development. Oestrogen also regulates the reproductive cycle and plays a role in behaviours associated with mating and maternal care.
Progesterone:
Progesterone is produced by the ovaries after ovulation and plays a crucial role in preparing the uterus for pregnancy and maintaining pregnancy if fertilisation occurs. It also influences behaviour related to maternal care and nesting instincts.
Cortisol:
Cortisol is a steroid hormone produced by the adrenal glands in response to stress. It helps regulate metabolism, immune response, and blood pressure. During adolescence, cortisol levels may rise in response to various stressors, including social interactions, environmental changes, and hormonal fluctuations. Elevated cortisol levels can impact mood, behaviour, and physical health in dogs.
Dopamine:
Dopamine is a neurotransmitter that plays a crucial role in the brain’s reward system and motivation. It is involved in regulating mood, attention, and movement. During adolescence, dopamine levels can fluctuate, affecting mood swings, exploration, and risk-taking behaviour in dogs. It is also involved in learning and memory processes.
Oxytocin:
Oxytocin is often referred to as the “love hormone” or “bonding hormone” because it plays a role in facilitating social bonding, trust, and attachment. During adolescence, oxytocin levels may fluctuate in response to social interactions, particularly during mating or maternal care behaviours.
While dopamine, cortisol, and oxytocin are not exclusively associated with adolescence or sex hormones, they interact with the hormonal changes occurring during this developmental stage and contribute to emotional and physical development in dogs.
Signs your dog needs to be neutered (true or false edition)
1.Aggressive behaviour – Maybe
Aggression in dogs can be misunderstood. It’s important to pay attention to what triggers aggressive behaviour so you can understand whether it’s fear based or hormonally influenced.
Typically, a true hormonal aggression is seen more in male dogs and occurs with other male dogs. This looks like dog on dog aggression and is only directed at other entire male dogs. In this instance, neutering your dog can stop the flow of testosterone which can help reduce the behaviour – although if the behaviour has been going on some time, you may have some training to do to solve it completely.
Fear based aggression can look the same, but it’s rooted in fear, nerves or anxiety. Cutting off your dog’s supply of testosterone in this instance is more likely to hinder their ability to grow in confidence than to solve the problem. In this scenario, I would hold off on neutering and focus on growing your dog’s confidence.
2. Anxiety, nerves or fearful behaviour – False
For dogs who are fearful, anxious or nervous, testosterone plays a vital role – and so I wouldn’t recommend neutering your dog in this scenario too early.
Testosterone can have a significant impact on confidence levels in dogs, particularly in shy or nervous individuals. Removing this important hormone can block your dog’s ability to grow in confidence in social interactions. Testosterone also plays a role in shaping the development of the brain’s reward system, influencing how dogs perceive and respond to social cues and challenges.
Rather than neutering, your dog will benefit from a focus on increasing their confidence and building trust so they feel more resilient and at ease.
2. Resource Guarding – Maybe
Resource guarding is reported as being more common in neutered dogs, however personally I don’t believe we can solely put this down to sex hormones.
Breed and genetics, as well as lived experience, can have a big influence on whether a dog resource guards or not. A dog who’s frequently had things taken away from them or who isn’t very confident will be more likely to resource guard.
It’s a complex topic and you can learn a lot more about resource guarding in dogs here.
4. Humping or sexual behaviour – Maybe
Humping is probably one of the most misunderstood dog behaviours. It’s not always sexual, despite what it looks like.
A dog who humps may be using it as a calming mechanism to relieve soaring adrenaline and cortisol. Or they may indeed be randy!
The difference between the two is quite easy to spot once you know how.
Sexual humping comes on less suddenly, the dog will usually posture, sniff and interact more slowly with the other dog before humping. Neutering may stop this behaviour.
Self soothing humping is usually more sudden and in response to goings on in the environment. For example, if your dog grabs a teddy or their bed when guests come over or humps erratically when overexcited, this isn’t sexual behaviour and neutering is very unlikely to eliminate it.
5. Roaming, escaping or not recalling out and about – Maybe
Neutering your dog isn’t going to magically deliver you a reliable recall or suddenly improve your dog’s ability to listen to you around other dogs.
However, if your adolescent dog goes wild for scents and can’t disengage from the environment, hormones may be playing a part. Dogs can smell a dog in season from a mile away, and scents left in the environment can become a hyper focus.
In this situation, your dog’s hormonal surges may be making it impossible for them to opt out of hunting scents and focus on you.
6. Marking and scenting – True
If your dog is starting to mark in the house (not just having an accident) but actually physically cocking their leg and scenting everywhere – this is a hormonal behaviour.
My own dog Neville was a chronic marker – he had a serious drive for marking and scenting and would frequently run off to leave his scent everywhere he could. In our situation, we decided to neuter him and the behaviour stopped.
It’s worth saying here though that you have to look at your dog’s behaviour as a complete picture. If your dog marks but is also nervous or fearful, then you have to weigh up the pros and cons.
7. Difficult seasons for female dogs – True
If your dog has a hard time during her seasons, then you might decide that it’s in her best interest to be spayed. Some female dogs can become suddenly grumpy or aggressive prior to their season and some will become almost mopey and sad when they’re in season.
Some female dogs also experience phantom pregnancies which extend the misery and can be very difficult emotionally and physically for a dog.
For these dogs, neutering may offer welcome relief from the hormonal effects of remaining entire.
8. Health reasons – Maybe
The influence of neutering on the health of a dog is variable by breed and a range of factors. Waiting for a dog to be fully matured and physically developed before neutering allows their joints and growth plates to fully form with the assistance of testosterone – for larger dogs, this can take as long as 18 months-2 years.
Other health conditions such as pyometra, cancer, obesity and urinary tract disorders can all be influenced by neutering. For accurate advice for your dog, it’s important to speak to your vet.
Chemical Castration for Dogs
Surgical castration can’t be undone, so if you’re in any doubt about whether this is the right decision for you and your dog, you may want to consider chemical castration.
Your dog receives a chemical implant that’s inserted like a microchip between your dog’s neck and back. This is a temporary measure that lasts around 6 months (although it takes 6 weeks to take full effect).
The chemical implant gives you an opportunity to see whether castration is right for your dog – but be aware, the first 3-4 weeks afterwards often see a transitory increase in hormonal surges until testosterone levels reduce.
Do dogs calm down after being neutered?
Neutering is not a magical solution to natural dog behaviours. Particularly during adolescence or puberty, it’s normal for dogs to become more confident, more independent, and to find it difficult to listen and focus.
The hormonal and developmental changes your dog is going through make it hard for them to control their impulses and to manage their conflicting desires.
Working on your dog’s impulse control and learning about their developmental stages can help you both practically and emotionally. Teenage dogs are hard work and it’s not spoken about enough!
Learn more about impulse control training here.
Get clued up on dog development and how to support them through each phase here.
Does neutering really reduce the overpopulation of dogs?
Surprisingly, empirical studies show no effects of desexing on population control in companion and shelter dogs despite desexing being consistently recommended. There is evidence for a population control effect in free-roaming dogs, where desexing also has benefits on zoonotic disease and bite risk. Population control in free-roaming dogs is mostly correlated with female, not male desexing.
(Urfer S.R., Kaeberlein M. 2009)
Is neutering ethical?
In many countries, desexing is strongly encouraged by veterinarians, while in other countries, routine desexing is considered unethical. Approximately 64% of male and female dogs are neutered in the US, 54% in the UK and 47% in Ireland. In contrast, in Germany and some Scandinavian countries, desexing can be performed only if there are clear medical indications for the procedure.
In conclusion
The bottom line is you need to consider why you’re thinking about neutering your dog and get appropriate advice from a professional for your unique situation and your unique dog. Should you neuter your dog? The honest answer is…. It depends!
If you’re thinking about neutering for behavioural reasons, reach out to an experienced positive dog trainer or behaviourist for advice, not a vet. Learn how to spot a good dog trainer here.
If you’re thinking about neutering for health reasons, reach out to a vet, not a dog trainer.
Already made your decision? If it’s a yes to neutering then get your dog prepared to happily wear a cone with this handy tutorial video.
Read Next:
Is your dog scared of the vets? Read this
Dog development stages explained
Understanding resource guarding in dogs (how to help your dog feel secure)
