labrador retriever

By Andrew Fischer

Neutering your Labrador: pros and cons

Are you considering getting your Labrador neutered? If so, you probably know that there are certain benefits associated with neutering. However, new research shows that there is also a number of risks connected with this surgery. For example, while neutering lowers the risk of testicular cancer in male dogs or mammary tumor in female dogs, it may increase the risk of obesity, hip dysplasia and other health issues. 

In this article we will look at how neutering affects your Labrador, why you should or shouldn’t neuter your pup and how you can prepare for it. 

We want to present all important information about neutering in an objective way, so that you can make a good decision about neutering your pup.

What is neutering, spaying and castration?

Neutering is the removal of dog’s reproductive organs. The term “Neutering” refers both to the removal of male and female reproductive organs. 

The male-specific term is called “castration”, while “spaying” is reserved for female dogs or any other female animal.


refers to the removal of the reproductive organs of female dogs. This usually involves a surgical procedure that removes the uterus and ovaries. A long incision is made in your dog’s belly, through which the reproductive organs are removed.

Female dogs can be also spayed using a laproscopic procedure. This procedure is very popular lately as it’s minimally invasive. Only two tiny incisions are needed and sometimes only the ovaries are removed. Without ovaries female dogs aren’t able to produce sufficient amounts of oestrogen which makes them infertile. (1)


Castration is the removal of testicles in male dogs. This usually involves a surgery to remove the testicles and to interrupt the production of sex hormones. 

The testicles are usually removed through a tiny incision in the scrotum. You have to wait a couple of months for the dog to become completely infertile. However, removing the testicles removes your dog’s source of testosterone, which is needed for example for your dog’s healthy growth and protection from diseases.

Male Labradors can be also neutered using a chemical castration. During this procedure a chemical is injected into the testicles. This method is not 100% effective, so if you want to have certainty that your dog is infertile you should go for the traditional surgical procedure. On the other the chemical castration may still enable a limited production of testosterone, which may have less negative side effects on your dog’s health. 

What are the effects of neutering my dog?

Since neutered dogs have lower levels of the male hormone testosterone, you may notice differences in all hormone related physical and behavioural features. Neutered dogs (unless neutered too early) usually grow more than intact dogs. Neutered dogs are also more prone to obesity  and to other physiological changes. Discuss possible side effects of neutering with your vet.

Aside from the missing testicles (which may be quite apparent especially in short-coated Labradors) a male dog that was neutered before maturity will look less masculine than an intact dog.

Recent studies show that castration doesn’t necessarily calm down an aggressive or excitable dog. Castrated dogs don’t become more lazy just because of castration. If they don’t move enough after castration they may get fat and more lazy, but castration by itself doesn’t lead to laziness and calmer character of dogs. 

Urine marking also significantly decreases after castration. Although neutered dogs will still lift their leg to urinate, this behaviour will happen much more rarely. One study shows that castration reduces urine marking in 80% of dogs.

The head of neutered male dogs may have more feminine features.

What’s interesting is that neutered dogs in average tend to grow a bit more in height than dogs that aren’t neutered. 

There are also several behavioural effects of castration on your dog. The reduced testosterone will likely eliminate your pup’s urge for sexual mounting and for roaming, which will diminish his exposure to various dangers outside. 

Recent studies show that castration slightly decreased roaming  in 70% of dogs and significantly decreased roaming in 40% of dogs. Similarly, mounting was reduced in 70% of dogs.

Why should I neuter my dog?

There are several reasons why people neuter their pups. Following points list the most common of them.

Birth Control

One of the main reasons why people neuter their pup is to avoid more puppies being born. Neutering is a permanent way to avoid your dog having puppies.

On the other hand, how many people leave their dogs free to roam around the neighbourhood unsupervised where it could produce offspring? Most people keep their pups secured in a supervised place all the time.

So as it shows, the most common reason why people choose to neuter their dog is not birth control nowadays, but because it’s believed that neutering will bring strong benefits to the dog in terms of health and behaviour.

Behavioral reasons

People also tend to neuter their dogs for behavioral reasons. However, only behaviours related to oestrogen and testosterone will be improved. If your dog has a bad behaviour because it’s untrained, neutering will not help improve his obedience. 

Neutering usually calms your dog down. There are instances when your dog may show territorial, sexual and other types of aggression. When recurring, this aggression may become a regular feature of your dog’s character. In such case, neutering may help. However Labradors are usually not aggressive. You can read more about how to stop aggressive behaviour in Labs in THIS ARTICLE

Another reason why people neuter their dogs is to deter them from territorial marking.

Male dog castration will supress his tendency run away and chase the scent of bitches in season.

By neutering your Lab, you can also stop him from humping on dogs, people and things. 

But on the other hand recent studies show that neutered dogs have many other behavioral issues. Sometimes a neutered dog may have more behavioral problems than an intact dog. Neutering effects on behaviour can significantly differ from dog to dog.

One recent study analysed how neutering affects behaviour in dogs and it concluded that neutering doesn’t improve the behaviour in any way. Based on the study results, non-neutered dogs aren’t more aggressive than neutered dogs. (1)

Another study found that contrary to the traditional view, neutered dogs were harder to train, more aggressive and fearful than intact dogs.

Health Benefits

Neutering your dog may have a couple of health benefits. Spaying can protect your female dog from mammary cancer and pyometra (uterus infections). If your male Labrador doesn’t have testicles, he can obviously avoid testicular cancer, testicular inflammation and other diseases connected to his reproductive system.

For a long time spaying bitches was wídely supported because it was believed that it greatly reduces the risk of getting mammary tumor. Some older studies showed that spaying female dogs before the first season eliminates that risk almost completely. More recent studies however question these findings. Although neutering your dog significantly reduces the risk of getting mammary cancer, it’s still possible your pup gets it. 

Neutering your dog also significantly reduces the risk of developing pyometra, which is a uterus infection that around 20% of all female dogs get at some point of their lives. The risk of getting pyometra is almost 100% avoided if you spay your dog. 

Dogs that don’t have one or both testicles fully descended are also advised to get neutered because they are at greater risk of developing testicular cancer.

Working dogs

When you have a working dog it’s also a good idea to neuter him/her. 

For example non-neutered guide dogs can become incapable of doing their job for a period of time. 

Especially spaying your bitch will free you from the inconvenience of twice yearly seasons.  Bitches in season are incapable of working for around 3 weeks every 6 months.

Bitches in season

Some people choose to spay their female Labrador in order to avoid the need to care for them in season, which lasts around 3 weeks every 6 months.

Some bitches can be somewhat difficult to manage when in season. It may be annoying for you and for your dog not to be able to go for a walk together for 3 weeks every half a year.

If you have a male dog, his tendency to run away and chase the scent of bitches in season will improve significantly. 

Mandatory neutering

Some governments may adopt mandatory neutering ordinances.

If you live in a country/region where neutering has become the norm, you may find it difficult to find enough support for taking any other course of action.

For example the Los Angeles County signed one of the nation’s toughest laws on pet sterilization. This law requires most dogs to be spayed or neutered by the time they are 4 months old. (2)

Decreasing the number of stray dogs

Neutering your dog will prevent him from impregnating stray dogs. This will reduce the number of unwanted dogs. 

There is a growing population of homeless and shelter dogs and around 700,000 shelter dogs are euthanized each year. 

You can help reduce this number by neutering your dog.

What are the risks of neutering my dog?

Although this topic is not well-known, there are certain risks associated with neutering your dog. 

These risks include an increased rate of arthritis, hip dysplasia and other joint problems, greater risk of lymphoma, higher prevalence of cranial cruciate ligament injuries, an increased rate of certain cancers (bladder, prostate), etc.

Female dogs that are spayed early face also a heightened risk of urinary incontinence and infectious diseases. Neutered dogs also have a higher incidence of adverse reactions to vaccination. 

In a 2014 study published by Christine Zink it was showed that neutered dogs were at greater risk of developing lymphoma, various cancers and had an increased fear of thunderstorms. The younger the age at which the dog was neutered, the higher the chance of developing these health issues. For example around 9% of early neutered male dogs were diagnosed with lymphosarcoma, which is a cancer of lymphocytes and lymphoid tissues. The prevalence of this disease in intact male dogs was only 3 %. 

For example, almost 10 percent of early-neutered males were diagnosed with lymphosarcoma, 3 times more than intact males.

Some studies show that neutered Labradors have a slower metabolic rate which makes them more vulnerable to becoming obese. Studies show that in order to maintain a healthy weight, neutered Labradors need around 20% less calories than intact ones. 

Another disadvantage of neutering is that it’s not reversible. If you will discover that your neutered Lab has an amazing genetic trait you would like to pass to his offspring, it will not be possible. 

Also, any type of surgery (including neutering) that includes anaesthetic may have a certain risk associated with it.

Often, the biggest concern is the post surgery recovery, since you need to ensure that the dog doesn’t lick excessively at its incision line, as it can significantly slow the healing process. 

You can read more about the negative effects of castration HERE

When should i neuter my Labrador?

Many Labrador owners ask me what age is best for preventive castration of Labradors?

Many smaller breeds can be neutered already around 8 months of age. However, for bigger dogs like Labradors, it’s recommended to wait until the dog is fully grown, which usually becomes around 2 years of age. 

Anyway, if neutering is advised for behavioural reasons, it might not be obvious until 2 years of age that there are some behavioural issues. 

It’s not recommended to neuter your dog before it reaches its full size because hormones like testosterone and estrogen play a vital role in the growth and development of dogs’ bodies. If you neuter your dog too early he/she will not have enough of these hormones to grow healthily. 

Many veterinarians report joint problems, hip dysplasia and other diseases in dogs that were neutered too early.

If you plan to adopt or buy a non-neutered older dog, it’s recommended you talk to your veterinarian so he can determine if your dog can safely undergo the neutering process. If your Lab is obese, it’s usually recommended for him to undergo a weight-loss program prior to any surgery. 

When neutering is carried out later in life, there may be more risks associated with the procedure. But you should know that your dog is never too old to be neutered, especially if there is a health reason for it, like in the case of a mammary or testicular tumour.

Undescended testicles

An undescended testicle (also known as cryptorchidism) is a testicle that hasn’t moved into its proper position before birth. 

This happens most likely due to a genetic predisposition. The undescended testicles are sometimes retained in the abdomen or anywhere in between the external sac and the abdomen.

Undescended (retained) testicles usually don’t produce sperm but often produce hormones.

Retained testicles in dogs have many negative side effects. They may be more prone to developing cancer. It’s therefore highly recommended that all dogs with retained testicles be neutered and both testicles removed. This will ensure that this genetic mutation is not spread further. 

My personal opinion on neutering Labradors

Based on the scientific evidence and my personal experience the adverse effects of neutering dogs may outweigh the benefits. Neutered dogs are more susceptible to various forms of cancer (besides the mammary cancer), which are hardly curable. Neutered pup may also easily develop joint problems and other health issues. 

Further, recent studies show that neutered dogs don’t improve their behaviour. On the contrary, neutering your pup may worsen his behaviour. 

Some health issues that are common for non-neutered dogs like pyometra can be treated quite effectively. 

If you can observe your dog closely when in heat to avoid an unplanned pregnancy, neutering may not be necessary. 

It’s likely that more studies in this field in the near future will hopefully make the pros and cons of neutering more clear.

If you have decided to neuter your Labrador you should check our “Step by Step” guide to castration HERE