Desexing Dogs & Puppies

The Latest Thinking on the Pros and Cons of Desexing Dogs

For years, the advice about desexing was simple: Neuter female dogs before their first heat and males around six-months of age. But all this has changed.

No longer is there simple one-size-fits-all advice about dog desexing. Your vet now has access to, and uses, evidence-based medicine when making decisions for individual pets. This is because we now know the dog desexing pros and cons vary depending on gender, breed, and age.

This article aims to guide you through why desexing dogs is a good idea (and when it’s not), what owners need to know about the impact of age on desexing, aftercare for their pet, and what to expect in the long term.

is it good to desexing

What is desexing?

Surgical desexing refers to the removal of testicles (dog castration or neutering in the male) or ovaries in the female (spaying).

Desexing female dogs prevents them from coming into heat and thus unwanted pregnancies. Whilst a neutered dog is unable to sire puppies and is less prone to roaming. All of which adds up to fewer unwanted dogs that might otherwise end up in hard-pressed shelters.

Typically, desexing is a surgical procedure done under general anesthetic. Desexing a male dog can be done temporarily with a hormone implant that lasts for approximately six months, but this is outwith the scope of this article.

Another previously strong argument for neutering dogs was the blanket statement that it reduces aggression. However, this too simplistic a view and in some circumstances makes the problem worse. What can be said with certainty is that a confident dog that shows any sign of wanting to bite a child or person, should be desexed.

In short, if you take one message from this article, it is to have a discussion with your vet about surgery and your pet, to decide what’s best for that individual dog.

What are the medical benefits of desexing my puppy?

Medical knowledge about the pros and cons of desexing dogs is an area where vet knowledge has changed significantly in the past few years. Most Veterinarians recommend desexing pets due to many benefits including to control overpopulation.

Benefits of desexing puppies

Pros & Cons of spaying female dogs

Let’s start with the females.

Everything in this world has an argument for and against it, and desexing a female dog is no different. In a nutshell here are the health arguments for and against spaying.

The benefits of desexing

  • Female puppy desexing makes the risk of mammary tumours less likely
  • Removes the risk of the life-threatening condition pyometra (pus in the womb)
  • Prevent accidental pregnancy with all its risks and complications
  • Avoids the nuisance of a six-monthly season

The drawbacks

  • Increased risk of urinary incontinence (a treatable condition)
  • Greater risk of obesity
  • Greater risk of cruciate ligament rupture
  • Large breeds – There is a link between early desexing and cancer of the bone (osteosarcoma) or blood vessels (haemangiosarcoma)
puppy smiling

Taken on face value this information may make the decision more confusing rather than easier. However, these bullet points don’t give any sense of proportion about the risks.

For example, one-in-four entire (un-neutered) female dogs may suffer from breast cancer. Therefore, at a 25% incidence, breast cancer is an extremely common condition, which requires corrective surgery, whilst malignant cancers are potentially life-threatening. Compare this with the risk of osteosarcoma, which stands at less than 0.1% (in fact 0.014%). Thus, the owner that decides against spaying because of worry about an uncommon condition, may place their dog at risk of a very common cancer.

Also, not all dogs are at equal risk of osteosarcoma. This condition mostly affects large or giant breed dogs and is almost unheard of in small dogs. Plus, the risk seems greatest for large dogs desexed at an early age. So owners of giant dogs can dodge this risk simply by desexing after 12-months of age. (More of this in “What age should I get my puppy desexed”)

benefits for puppies

Pros & Cons of neutering male dogs

Switching focus to the males, here’s a summary of the pros and cons of desexing male dogs

The benefits of desexing

  • Removes the risk of hormone-related prostate disease (benign prostatic hyperplasia BPH)
  • Makes the risk less likely of a hernia forming beside the anus
  • Reduces the risk of roaming, male-on-male aggression, and bites to people

The drawbacks

  • Slightly increased risk of prostate cancer
  • Dog desexing increases the risk of obesity
  • Large breeds – Increased risk of hip dysplasia, cruciate ligament disease, and osteosarcoma

To sum up male pets it’s important to understand there is no strong health argument in favour of desexing, such as there is for the girls. The main health advantage is to reduce the risk of benign prostatic hyperplasia. But happily, should the latter occur is is a treatable condition and so there is less pressure for early neutering.

The other arguments for castration are behavioural (such as roaming and aggression) and to minimize the stray population. But for the responsible owner that trains their dog and doesn’t allow them to roam, the need for surgery is not clear cut based on the health advantages to the dog.

This doesn’t mean male dogs should not be desexed, just that it’s important to talk through your reasons for the operation with a vet before booking the dog in. You may be surprised by their advice, especially for sweet-natured dogs!

Do dogs change after being desexed?

OK, setting the health debate aside, how does desexing surgery impact a pet emotionally and influence their behaviour?

How does desexing affect a male dog?

Castrating a male dog lowers their testosterone levels. Testosterone is responsible for a lot of less desirable male habits such as territory marking, the drive to find a mate, being over territorial, and aggressive to other dogs. Thus, desexing can help to make dogs with these unwanted behaviours into better pets.

However, many entire male dogs are perfect sweethearts and have no need for such correction. Indeed, there is an argument against surgery for anxious male dogs. An anxious dog may be aggressive out of fear, and desexing male dogs which lowers their testosterone or ‘brave’ levels may make their anxiety worse (and therefore their aggression) rather than better.

It is therefore very important to talk through the reasons for desexing with a vet, before going ahead to ensure you don’t jump in the wrong direction.

Female dog behaviour after desexing?

Female dogs generally cycle twice a year. A spayed dog pretty much acts like she does in-between heats. There is usually no dramatic difference to her character or personality, and in fact, may become more loving and attentive when freed from the massive hormonal surges associated with her oestrous cycle.

Does desexing calm a dog?

Yes, the op often results in a calmer, more attentive pet. However, this is no magic bullet and regular obedience training using reward-based methods is every bit as important as the scalpel when it comes to better behaviour. For males that are super-energetic, easily distracted, and difficult to control then desexing may help give you the edge but this is only part of the picture. You still need to give the dog plenty of interactive exercises and commit to training.

calm dog after procedure

What age should I get my puppy desexed?

It shouldn’t surprise you that there are arguments for and against puppy early or late desexing.

Early / Prepubertal desexing

If you get a puppy from a rescue, you may find them already desexed. This is due to the increasingly popular practice of puppy desexing at a very young age, such as two to three months of age. The main driver for this is to reduce unwanted pregnancies and the numbers of unwanted dogs, with there are already being too many dogs for too few homes.

It may sound alarming to put such a young puppy through an operation but in fact, the pups cope very well. Plus, evidence now tells us that this has little or no impact on the dogs’ long term health.

To look at this in more detail, on the plus side of desexing a puppy, the youngster recovers quickly because the womb or testicles are immature and thus the surgical time is much less. Modern anaesthesia techniques also mean no increased danger despite the young age, and modern drugs can safely keep the patient pain free.

On the minus side, the sex hormones play a part in telling the bones when to stop growing. When a puppy is desexed at a young age, they lose this feedback and so the bone growth plates stay open for longer. This means the dog may be slightly leggier as an adult than they might otherwise be. This is all well and good, because it doesn’t mean the puppy will become a giant, but it may have implications for the ligaments that hold the joints together.

Current thinking is that early desexing of pets may add to the risk of knee-ligament rupture in later life. Also known as cruciate ligament rupture, this is a potentially debilitating condition that may require expensive surgical repair.

But again balancing the risks, smaller dogs are those least affected by early desexing. However, large or giant breeds do have a credible increased risk of conditions such as osteosarcoma. Thus, for the bigger dogs it does seem sensible to desex sometime after their first birthday, but before their second. After two years of age, this is classed as late desexing, which comes with a new set of pros and cons.

Late desexing

The main disadvantage against late desexing is that the cancer-protection factor is lost for the females. There is less pressure for males to be desexed, because of the lack of a strong health argument in favour of desexed dogs. However some states in Australia, it is compulsory to desex puppies when they are 6 months old. South Australia (Section 42E of the Dog and Cat Management Act 1995) & ACT (Section 74 of the Domestic Animals Act 2000) – there are some limited exemptions. This is to limit backyard breeders and to reduce the number of abandoned animals.

What is the best age to desex a male dog?

If you decide to desex a male dog consider waiting until after their first birthday, and possibly even 18-months old for giant dogs. This is of course providing the male is not aggressive and a danger to people, in which case desexing must be the priority.

What is the best age to desex a female dog?

For small breeds, either before her first season or between the first and second heat is ideal.

For large or giant breeds, it’s best to wait until she is at least one year old, but if possible before her second season or second birthday.

Oh, and in case you were wondering, the idea that a female dog should have one litter is nothing but a myth. There are no health benefits to her, and indeed pregnancy puts her at risk of conditions associated with difficulty giving birth or nursing pups.

Is desexing safe?

Desexing is an operation that vets never become complacent about, but equally, they do a lot of these surgeries. This means they are highly skilled and the risk of problems is low. Also, modern anaesthetic agents and pain relief make things as safe as possible.

Before desexing what every dog parent should do

Before desexing, work with a vet that is prepared to spend discussing every aspect of the procedure with you.

No-one is saying dogs should not be desexed, but more the desirability and time of the op vary with individual animals. Forget the one-size-fits-all advice, and go with a plan tailored to the needs of your pet. A large dog should be desexed later than a small one, to dodge the risks. Whilst smaller breeds have the option for early desexing, for maximum cancer sparing effect. In short, talk to your vet.

The Desexing Procedure

Male or female, the desexing procedure requires a general anaesthetic. The animal has a pre-op check with the vet to make sure they are fit and well for anaesthesia. They then have a pre-med injection made up of a sedative and pain relief.

Once under the anaesthetic, a patch of fur is clipped to make the area surgically clean. For the girls this shaved area is on their belly, for the boys, it’s just in front of the scrotum. The vet then scrubs up and makes an incision in this area, and removes the appropriate sex organs.

Sterilization tools

For the girls, this surgery commonly involves removal of the ovaries and womb, although there is now a trend for only removing the ovaries. The latter is slightly less invasive and so the patient recovers more quickly. For the boys, the op requires the removal of both testicles. (Performing a dog vasectomy is rare because the main reason for castration is to eliminate the effect of the male hormone testosterone.)

The time the operation takes is around 20 – 60 minutes, after which the vet suture the wound and wake the animal.

From start to finish the recovery time is around 10 to 14 days. During this period the dog mustn’t over-exert themself as this can lead to complications.

How much does it cost to desex a dog? The cost of desexing male dog is slightly lower than that of a female because the surgery is slightly less complex. On average an owner can expect to pay a couple of hundred dollars for the procedure, with some charities offering cheap dog desexing on welfare grounds.

How should I care for my puppy after desexing – treatments?

Once home keep the pup warm and quiet. Your vet will advise feeding a bland meal that evening, as the anaesthetic may cause an upset tummy. Keep them on a lead when they go out to the toilet, mainly so they can’t chase wildlife and do themselves a mischief.

Equally important is to prevent the dog from licking the wound. Contrary to popular belief, dog saliva does not have healing properties and is likely to cause an infection. Also, check the wound daily for any redness, swelling, or discharge. If you are at all worried, contact the vet for advice.

Most vets check the pet after three days, to ensure they have recovered fully from the anaesthetic. This is followed by an appointment 10 to 14 days post-surgery, to sign the patient off.


The most common post-op complications include wound infections or damage (due to licking) This is why pets need to rest for 7 – 10 days and to wear a cone-of-shame or surgical-suit if they are likely to lick.

Weight gain

Now here’s a thing. One study showed 66% of desexed dogs were over-weight, compared to 37% of intact (entire) animals. But what’s interesting is those chubby desexed dogs became over-weight within two years of surgery. The researchers concluded that simply reducing calorie intake by around 5%, immediately after the op meant dodging the bullet of weight gain.

The reason for this is that the reproductive organs burn calories. When these organs are removed, those calories are no longer needed. Keep feeding the pre-surgery amount, and the dog simply gets too much food. To prevent this, reduce their portion size slightly after desexing.

Cost of Desexing a dog

Prices for neutering dog may not be the same in each suburb, but below table would give you an idea of the price of desexing. Most clinic’s prices are based on the weight and the sex of the animal (female dog desexing cost would be bit higher), where smaller breed would cost less and giant breeds will cost more. Contact your local council, as they may have a voucher scheme.

Female Male
Small dogs (below 10kg)  Around $200 Around $180
Medium (10-20kg) Around $250 Around $220
Large dogs Around $400 Around $380


  • Is desexing painful for Dogs?

    Desexing surgery is major surgery. The good news is that modern drugs and pain-relief protocols mean your pet does not need to be in pain.

  • “Will it cause my pet to become fat?”

    Desexing means the body burns slightly fewer calories. Weight gain is less likely if you feed slightly less post-surgery.

  • “Are there any issues with any particular breeds”:

    As mentioned above, giant breeds require careful consideration about the timing of desexing surgery in order to minimize any slight risk of complications in later life.

  • “Will my dog lose its “guard dog” instinct?”

    Once established as a behavioural instinct, guarding is not affected by desexing

  • How much does it cost to desex a male dog

    This vary to each vet clinic, how every mostly the price depends on the weight of the dog, and the price range would be $180 – $450. You might be eligible for discounted desexing program, please contact your local council or vet.

  • Cost of desexing female dog

    price for a female dog would be bit higher than a neutering male dog, and same as males prices depend on the weight. The price range would be from $200 to $450 in most vet clinics in Australia.

  • Does desexing calm a male dog

    Yes! Often after desexing, dogs have more relaxed temperament