Does neutering change dog behaviour?

Choosing to neuter your dog can feel like a big decision, but it’s a safe and routine operation.


While ‘neutering’ can refer to both male and female dogs, there are more specific terms. A male dog is neutered or castrated, which means their testicles are surgically removed. A female dog is spayed, which is the surgical removal of their uterus. As a result of these operations, both genders will be unable to produce puppies and their natural hormone production will decrease.

Most people choose to neuter their dog when they are still a puppy, though this shouldn’t be done until the puppy is at least six months old. It’s best to speak to your vet for advice on when it would be best for your dog’s breed.

Does neutering change a dog’s behaviour?

Likely, yes. But vets recommend that owners neuter their dogs for a number of reasons.

General benefits of neutering include managing your dog’s reproductive instincts, preventing any unwanted offspring and sometimes calming hormonal behaviour. However, this can vary between dogs, so it’s best to ask your vet’s advice first.

What are the signs your dog needs to be neutered?

If your male dog is showing signs of overconfidence or even aggression, neutering can help – but you can also look into other options first, such as training.

If your dog is humping objects or regularly displaying actions akin to mounting a female dog, neutering can be a good solution. While humping isn’t always sexual in nature, neutering can help to balance a dog’s hormones, which can help to reduce overly excitable or aggressive behaviour.

Dogs who aren’t neutered are also highly sensitive to female dogs – especially when they are in season. During a female dog’s season, she’ll become attractive to male dogs due to the scent she gives off and you may find that she’s keen on trying to mate. This lasts for around 18 days.

Likewise, an unneutered male dog’s behaviour can become unmanageable if they smell a female dog in heat. They may even try to escape from the house or garden to find her, which puts them and others in danger.

Female dogs may need to be spayed if they struggle hormonally when they are in season, such as howling, barking or trying to escape, or if they are experiencing phantom pregnancies. Sometimes spaying is a good idea if they have already had a litter of puppies and there were complications in the pregnancy, or if future pregnancies would be unwanted.

How does a female dog’s behaviour change after spaying

The answer to this question depends on your dog’s personality before she’s spayed. As spaying a dog does affect their hormones, it will impact hormonally-driven behaviour. This can mean a reduction in aggression, irritability or overt sexual behaviour. The reduction of these traits can mean your female dog will be more relaxed, calmer and could be a lot happier.

While a female dog’s behaviour will change after spaying, the main benefits are usually more health-related. These can include a reduced chance of some cancers or potential tumours, and spaying a female dog can also result in the likelihood of theft. However, the main reason to spay a dog is to remove any risk of pregnancy, rather than to manage challenging characteristics.

If your female dog experiences phantom pregnancies, these can be distressing. In these cases, your dog believes she’s pregnant, so she can begin to nest and prepare for motherhood. She can be extremely unsettled, have increased anxiety and even show signs of depression. She can fixate on her toys as though they’re her puppies, which can lead to aggressive behaviour. Physically, she may have a reduced appetite, be lethargic or have signs of lactation.

Spaying will help rebalance the hormonal issues your dog is experiencing, so it could be beneficial for your dog’s overall behaviour and wellbeing.

How does a male dog’s behaviour change after neutering?

Male dog behaviour after neutering is likely to change, but it is difficult to predict without knowing your dog’s current characteristics.

There are many reported positive behaviour changes after neutering. If your dog is aggressive, overconfident, unmanageable or regularly tries to escape to get to female dogs, then neutering can reduce these behaviours.

It’s worth noting that many adverse male dog behaviours – such as trying to hump objects – can be remedied by more exercise, consistent or professional training, and changes to their diet. It’s a good idea to try these options before opting for surgery.

What are the overall benefits of dog neutering?

Anecdotal reports indicate that neutered dogs appear to be more peaceful, relaxed and happier.

In some instances, neutering can adversely change your dog’s behaviour. For example, if they’re anxious or nervous before the operation, this behaviour can be made worse. However, this is counteracted by the health benefits that can come with neutering, such as the risk of your dog developing certain cancers.

The age of your pet has an impact on the benefits of neutering, especially if your dog is still a puppy, so make sure to do some specific neutering research.

As a result of the possible unknowns, it is advisable to discuss the various pros and cons of neutering your dog with your vet, as well as a behaviour specialist, to help you come to the best decision for you and your dog.


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