Dog Neutering: The Pros and Cons

Looking to spay and neuter your dogs? Spaying and neutering can be very difficult decisions to make.

Dog neutering can be an extremely emotive subject and there can often be strong opinions on both sides of the fence; for and against.

I am generally an advocate for spaying and neutering although much of my decision-making process has come from having been involved in animal welfare and having seen the number of unwanted dogs there are already in the system looking to be adopted.  I do recognise however that it is an issue that is not clear cut, there are lots of grey area and there are pros and cons that need to be weighed up.  Every dog is an individual, there are breed traits to take into account and their size and age too.

It seems that the evidence suggests that there are more clear cut health benefits for spaying females but for male dogs, there can be some potential health impacts that could be created by neutering that need to be taken into account when making the decision.

To allow you to make a more informed decision, we would always recommend you speak to your vet, a good behaviourist if appropriate, and consider all the facts before making a decision.

It is important to also consider the motivation behind your decision.  The health debate is a very valid one but sometimes a decision is made based on irrational emotions and long-held myths and these will not usually benefit your dog.

Whether to neuter your dog or not can be a big decision and one that you need to be able to understand all the facts before taking the plunge 

What is Neutering?

Neutering surgery, or de-sexing, is when the reproductive organs are surgically removed from male or female animals.

Spaying is the term used for female neutering surgery.  It usually involves the removal of the uterus and the ovaries.  It is possible to also have just the ovaries removed through keyhole surgery.  Comparing spaying and neutering, spaying is a slightly less invasive surgery and requires less recovery time too.

Castration is the term used for male neutering and this is when the testes are removed to eliminate the possibility of reproduction.  This removes the possibility of testicular cancer entirely. It is generally a less invasive surgery than spaying and dogs generally make a very speedy recovery. It can take around two to four weeks for a dog to be considered fully sterilised after castration as it can take this amount of time for all of the hormones to leave their body.

It is also possible for male dogs to have a hormone implant that blocks the production of testosterone for 6 to 12 months.  It can take up to six weeks for the hormone levels to drop but this is another possible option if you do not want to opt for castration straight away.

There are medications available to suppress a bitches season but these are generally not used very commonly anymore due to their potential side effects.

Pros of Castrating/Spaying Your Dog

1. Helping to Control the Dog Population

The most obvious reason for ensuring that your dog is neutered is to avoid the risk of contributing an unwanted pregnancy when there are already so many animals struggling to find homes.

Obviously, this is true if you have a bitch but, actually, it can be unneutered males that cause the biggest problem as they will actively seek out females in heat and can escape from their homes or whilst on a walk and mate with a female without you even being aware they have done it.  Owners can often underestimate the drive and determination an unneutered male will have in his quest to reach a bitch in heat.

If you have a multi-dog household it is even more important to consider neutering as it is much more difficult to manage to avoid accidents in this situation and two intact males may tussle more frequently.

There are already so many homeless dogs, do you want to inadvertently add to the problem?

2. Prevent the Risks That Come With Pregnancy and Birth

If you do have a bitch that is pregnant, this in itself carries its own risks.  Not only can there be pregnancy-related complications but there can be a risk of infection through the reproductive process for the male and female.

3. Reduction in Risk of Mammary Cancers

Mammary tumours are extremely common.  It is believed that around half of those discovered turn out to be malignant.  Mammary cancers are the most common type of cancer contracted by female dogs. The risk of developing this type of cancer increases after the second season.  It has been shown that neutering greatly decreases the risk of contracting this.

A study conducted by the National Cancer Institute way back in 1969 showed that only 0.5% of bitches spayed before their first heat would go on to develop mammary tumours, 0.8% for those before the second heat and 26% of those spayed after the second heat.

This is probably the biggest health benefit argument for spaying.

4. Prevention of Pyometra in Bitches

Pyometra is a serious, life-threatening uterine infection that can develop in unspayed bitches.  A study conducted in Sweden, where elective spaying is not particularly common, showed that around 23% of unspayed females develop this infection of the womb.  It can be an extremely serious, fast developing issue that can lead to death if left untreated or caught too late.

5. Castration Reduces the Risk of Conditions Associated With the Perineum

Whilst relatively uncommon in dogs, Perineal Hernias (the area around the anus) do occur and it has been evidenced that neutering reduces the risk.  Other Perineal associated conditions, such as Perianal Fistulas, are often attributed to hormonal influence and so it is believed that neutering can reduce the possibility of developing these too.  Whilst these conditions are not seen regularly it is useful to be aware of this benefit of neutering.

6. Reduces the Risk of Prostate Disease

Benign Prostatic Hyperplasia is the most common type of prostate disease and this can develop into Prostatitis. Whilst it is not usually a life-threatening condition it can be extremely uncomfortable, impacting on your dog’s quality of life.   A study conducted in 2007 showed that around 28% of unneutered males were reported to have Prostatitis but that castration greatly reduced this possibility.

7. Prevents Your Bitch from Having a Distressing Phantom Pregnancy

It is not an uncommon phenomenon for a bitch that has come out of heat to have a phantom pregnancy.  It can be a very distressing and confusing time for them and they display signs of being pregnant when they are not.  They may start to nest and nurse more, they may develop an extreme attachment to a particular toy or another item, they can even develop a swollen tummy and start to secrete from their mammary glands.  They can also become depressed, lethargic and lose their appetite.

Whilst it will pass, it can be very stressful for them and it is also not a nice thing to witness and it is not uncommon for it to happen more than once.   Spaying your bitch will generally stop this type of behaviour from happening.

Sometimes a phantom pregnancy can result in a bitch developing an unnatural obsession with a particular toy 

8. Removes the Stress That Can Come with a Bitch in Heat

Have you ever taken a bitch in heat for a walk around the local park?  You will often start to garner a lot of unwanted attention from any male dogs.  If they are off lead and unneutered there is a risk that they could attach themselves to your Bitch and an accident could happen.  Even if they don’t manage this, they can be extremely persistent and it can be distressing your dog and you.

Often, when a bitch is in heat you have to keep them on lead and walk in areas that you are unlikely to receive this type of attention.  Spaying obviously, removes this worry altogether.

Some bitches can also become particular hormonal around the time of the season (a bit like a doggy version of PMT) and obviously spaying will save them from this too.

9. Your Dog Will Have Less Desire to Mark Their Territory

Male dogs often have a desire to mark their territory as part of a testosterone-fueled display.  Sometimes they will even do this in their own home and you can find unwanted puddles or marking up the side of your couch or bed.  Whilst there are lots of management techniques and training techniques that can be put into place to help avoid these even if your dog does stay intact, neutering does often remove the desire to mark in a territorial fashion.  If you are not planning to neuter but are looking to try to stop this marking. It is a good idea to invest in a good odour remover, go back to basics with house training, use a belly band whilst you work on it and always reward marking outside but not in.  If you see them start to sniff and cock their leg, get them outside or distract them and ask for an alternative behaviour.

10. Your Dog May Be Less Likely to Roam

An unneutered male that gets the scent of a bitch in heat can be extremely determined, even rather frantic, in their attempts to reach her.  In the home, they may whine and pace and be generally unsettled. They may also try to escape and if they do they can roam unsupervised. This is dangerous and can also result in an unwanted litter.  Whilst you make a decision it is important to make sure that your home and garden are all escape proof.

Your dog may go to extreme lengths to get to a bitch in heat, including trying to escape from the garden! 

11. Your Dog May Be Less Likely to Display Humping Behaviours

Humping behaviour often occurs due to your dogs levels of arousal.  Whilst neutering will not guarantee to stop this behaviour, there is a good chance that it will help.  If you do not wish to neuter, there are lots of training techniques that can be applied to discourage your dog from exhibiting this type of behaviour.  Distraction techniques, giving them something else fun to do can be useful and rewarding them for offering alternative behaviours can work wonders.

When they are around a bitch in heat though, it is best to just remove them from this situation.  It can be too much to ask for them to be easily distracted in this scenario!

Cons of Neutering Your Dog

1. You May Have to Watch Your Dog’s Waistline More Carefully

It is true that the changes in hormones after neutering can mean that a dog may have a propensity to put on weight more easily.  It is very easy to manage this though by just monitoring their meal intake carefully, increasing their exercise and being sensible about what extras you may be giving them.

It is important to watch that your dog does not put on weight after being neutered, obesity can bring on a whole host of health problems 

2. Complications as a Result of the Surgery

It cannot be ignored that every surgery does have an element of risk.  The risk is small though and it should be balanced up with the other pros and cons on the list.

To put it into perspective, a study published in the Journal of the American Veterinary Medical Association reported that death rates from this type of elective surgery are less than 0.1%.

3. Possible Increased Risk of Bladder Cancer

Transitional Cell Carcinoma, found in the urinary tract, are more common in female dogs. The studies suggest that there is a slightly greater risk of neutered dogs contracting this than those that are intact.  There are a number of breeds that have a very strong predisposition towards this type of cancer and it has been suggested that this could have had an impact on the results.

4. Increased Risk of Heart Tumour

Hemangiosarcoma is the most common type of heart tumours in dogs.  Large breed dogs are more predisposed to this condition and the long term prognosis is not generally favourable.  Studies have shown that there is an increase in the risk of developing this disease if neutered (5 times greater in females and less than 2 times for males).

5. Risk of Developing Hypothyroidism

It is believed that the sex hormone can have an impact on the condition of Hyperthyroidism and this may explain why there have been studies showing that neutered dogs have three times more chance of developing this condition than intact dogs.

It is a condition that can be managed with the right treatment though.

6. There Are Studies That Show Rare Links with Joint Problems as a Result of Neutering

It has been evidenced that neutering can lengthen the limbs if it is done before whilst the dog is still growing and before the actual growth plates close.  Looking at this angle would suggest that neutering before one year old, or 18 months for a larger breed could be detrimental.

It is important to note, however, that this elongation of the limbs has not conclusively been proven to contribute to breaks or other joint problems.

There are also studies that suggest there may be a link between neutering and hip dysplasia and cranial cruciate ligament ruptures.

None of these studies are conclusive though and there is also a suggestion that some of these issues could relate more closely to the dog’s weight, overall condition and genetics.

If your dog puts on weight after neutering this could have an impact so it is important to always make sure your dog maintains a healthy weight.

There is no conclusive evidence that neutering results in joint problems for dogs

7. Spaying of Bitches Carries a Small Increased Risk of Incontinence and Urinary Tract Infections

It has been evidenced that neutered females carry an increased risk of developing urinary tract infections.  Although again there is also evidence to suggest obesity can sometimes cause this condition, again another reason to watch your dog’s waistline.  It is also shown that if a bitch is neutered too early there can be problems with a recessed vulva and this too can lead to urinary tract infections.

There is an increased chance of a spayed bitch developing urinary incontinence but the numbers are still relatively low and, if this did occur, it is a condition that can be managed and treated well.  The risk increases if the bitch is spayed before 3 months old, so this is another supporting factor for not neutering too early.

8. Risk of Bone Cancer in Large Breed Dogs If Castrated Too Early

Large breed dogs are seen as being more at risk from the bone cancer Osteosarcoma and it has been found that neutered dogs are more at risk of developing the disease than intact ones.

A study that was conducted in 2002 looking at bone sarcoma risk in dogs suggested that neutering before the age of one was evidenced to increase the risk of developing this disease.  This does then suggest that larger breed dogs should perhaps be neutered slightly later than others. The study did also make note though that the neutered dogs in the study lived longer than the intact ones so this could have been why there was more evidence on cancer in the neutered group.

Is There an Increased Risk of Developing Prostate Cancer?

This is a really tricky one as there have been a number of studies conducted that provide varying different results.  Some suggest that cases of prostate cancer are reduced as a result of neutering, some suggest there is no impact and a few recent studies suggest that neutering could potentially create an increased risk of developing this type of cancer.

It is a rare form of cancer in dogs but it is an aggressive type that does not have a good prognosis in the long term.

As it stands, there does not seem to be any clear cut evidence on whether neutering has any impact on this type of disease.  We will just have to wait to see if any further studies are released offering more conclusive evidence one way or the other.

Other Grey Areas

There have been some studies conducted that have suggested there is a possible link between neutering and diabetes and canine dementia but the results so far seem inconclusive.

Neutering and Dog Behaviour

This is a difficult one.  Neutering should never only be considered as a means to change your dog’s behaviour.

There are a number of studies and plenty of anecdotal evidence that neutering, especially for male dogs, can reduce certain types of problem behaviours.  You may see less aggression or dominant behaviour towards other male intact dogs, or other dogs in general, you may also, as already explained, see a reduction in territorial marking, a desire to roam and humping behaviours.

There is a limited amount of evidence however that suggests that in rare cases spayed females can start exhibiting more aggressive behaviour. A study conducted in 1983 suggested that a higher number of spayed bitches exhibited aggression than those that were intact.

If your dog is showing any aggressive behaviour I always recommend seeking out a qualified dog behaviourist.  You first need to establish why your dog is acting aggressively. More commonly it will be due to fear, reinforced behaviour, being in pain with an underlying injury or medical condition or some other factor.

If your dog is showing aggressive behaviour, always seek the help of a qualified behaviourist before considering neutering as a solution.  It is likely something else that is triggering the behaviour rather than a hormonal issue 

Dog Neutering Myths

There are some long-held fallacies about neutering that I thought it would be good to dispel

1. Having My Dog Neutered Will Stop Them Being over Excitable

Some people ascribe to the belief that neutering will ‘calm their dog down’.  Whilst it may help when your dog is excitable around a bitch in heat, if your dog is just generally excitable and bouncy then that is more likely their general personality, lack of stimulation or some other trigger that is setting it off.  It is better to look at training, management techniques and opportunities for more stimulation to deal with an over excitable dog rather than looking to neutering to solve the issue.

2. Having My Dog Neutered Will Completely Change Their Personality

You are not going to see any noticeable changes in your dog’s personality after neutering.  Yes, the may not be so inclined to roam or hump but they will still be the same dog they always were.

3. I Will Be Emasculating My Male Dog

This is one of the most commonly held misbeliefs, especially from men.  Your dog does not think in the same terms that we do and it is certainly not going to negatively impact how they feel about themselves!

4. It Is Better to Let My Dog Have One Litter

Dogs, unlike humans, do not feel ‘broody’. There are no proven behavioural benefits in letting your bitch have a litter.  It is also irresponsible to breed without having the right experience or motivation.

If You Are Keeping Your Dog Intact Make Sure You Are a Responsible Owner

If you do decide to keep your dog intact then it is all about ensuring you are being responsible.  Don’t allow your dog the opportunity to roam unsupervised, make sure that you are careful about where you walk when you have a bitch in heat and don’t allow a testosterone-fuelled male dog to bully, hump or pester other dogs unfairly.

As you consider whether to spay or neuter your dogs, remember that spaying and neutering does not have to be expensive – there are low cost spay neuter options that also get the job done.

Always keep a bitch on heat on a leash and try to walk in areas that you are unlikely to come across off leash males