Should you desex your dog? What you need to know about desexing

April 8th, 2017
Should you desex your pet?

Should you desex your dog? Laura Greaves examines the arguments for and against whether you should desex your pet.

More than 90 per cent of Australia’s registered dogs are desexed, which shows that most owners who are responsible enough to register their four-legged friends are also responsible enough to have them desexed.

But, that figure doesn’t take into account the thousands of dogs around the country that are not registered with their local council, many of which are unlikely to be desexed.

And what about the 10 per cent of registered dogs that aren’t desexed? What’s stopping their owners?

Desexing: the lowdown

Desexing is performed by veterinarians in sterile conditions under full general anaesthesia. In females, known as bitches, the ovaries and uterus are completely removed. In males, both testes are removed, eliminating the source of sperm and the main source of the male sex hormone, testosterone.

While vets advise keeping newly desexed dogs quiet for several days after the procedure, most make a complete recovery within a week or two.

As for when your dogs should be desexed, recent research suggests that desexing while your male dog is young — as early as eight weeks, providing he weighs more than 1kg — can be worthwhile. But it’s important to be aware that, the younger the dog, the more care is required in anaesthetic and recovery.

Thinking has also changed in the veterinary community with regard to when bitches should be desexed. Previously, it was advised that bitches be desexed by six months (26 weeks) of age, but it is now recommended by 20 weeks.

“Veterinarians vary a little in their personal recommendations according to the equipment they have available and their personal views on complex science, but nearly all veterinarians now agree that last century’s recommendations are out of date,” says Dr Joanne Sillince, veterinarian and managing director of Pets Australia (

Bitches can be desexed as early as eight weeks of age, however, early desexing carries a slightly increased risk of incontinence in later life.

It’s never too late to desex — there is no ‘best before’ age for either male or female dogs. In fact, the risk of certain diseases increases with age, so desexing is even more important for older dogs.

“The only reason not to desex an older dog is if it has medical problems so severe that anaesthetic is a risk,” explains Dr Sillince.

The case for desexing

According to Dr Sillince, the most compelling reason to desex a dog is the one that tends to frighten owners the most: cancer.

A desexed male will never develop testicular cancer, while desexed bitches will be free of uterine and ovarian cancers and be much less likely to develop mammary tumours. Desexing also significantly reduces the incidence of prostate problems in males.

“Not only that, but it also eliminates a truly horrible infection of the uterus called pyometra, which can kill bitches,” Dr Sillince says. “If you had the chance to eliminate all these diseases for your dog, wouldn’t you want to do so?”

Several scientific studies clearly show that desexed dogs live longer on average than entire canines [those that haven’t been desexed].

Dogs that are desexed early also avoid learning adult sexual behaviours such as fighting for territory, excessive urine marking and resource-protection aggression. “That means your doggy friend focuses on you and your family instead of the local doggy girlfriend,” says Dr Sillince.

The decision to desex has benefits for the wider community too. “The most obvious reason to desex is that it stops puppies. A bitch can produce up to 30 puppies per year, but a male dog can produce literally hundreds,” explains Dr Sillince. “It’s important to do your civic duty by getting your dogs desexed.”

The case against desexing

Let’s be honest, if you are a responsible dog owner, there is really no genuine reason not to desex your pet. However, there may be reasons not to desex particular dogs at particular times.

“You shouldn’t get your dog desexed if it weighs less than 1kg or if your bitch is pregnant or in heat, unless you have high-level veterinary care available,” advices Dr Sillince. “Getting your pet desexed after a recent severe injury is also not advised — let them recover first.”

You may also decide not to desex because you plan to breed your dog, but Dr Sillince urges careful consideration before breeding. “Nearly everybody who really loves a dog says, at some point, ‘This dog is so great I really ought to breed from it’ but is this really the case?” she asks.

“There are so many good dogs in the world. As extraordinary as your pet is, wouldn’t breeding from it just destroy that uniqueness? Is it really worth reducing your pet’s average lifespan just to try and copy a dog that you have worked to make special?”

Some dog owners worry that it’s not fair to desex a bitch before she has had a litter. Such concerns are unfounded — there’s no evidence to suggest female dogs are physically or psychologically better off if they have had puppies.

“In fact, many are worse off. They are at increased risk of pyometra if desexing is delayed and in some cases, bitches put so much calcium into milk for their pups that they draw it out of their bones,” explains Dr Sillince.

She says the belief that we somehow ‘deprive’ dogs by not allowing them to procreate is simply a reflection of our increasing anthropomorphisation [attributing human characteristics to animals] of our beloved pets.

“Dogs live in the moment. There is no evidence that they think about what might have been. If they haven’t had puppies, it’s not likely that they miss them. This old wives’ tale needs to be consigned to the garbage bin of history.”

Other dog owners cite the fear that their pooch’s behaviour will change dramatically as their reason for not desexing. Again, the science suggests there’s no reason to worry. “Most behaviour changes (after desexing) are positive, progressive and less dramatic than people think,” says Dr Sillince.

The animal welfare argument

As Dr Sillince points out, desexed dogs are physically unable to sire or carry puppies. With hundreds of thousands of dogs and puppies abandoned and surrendered every year, it goes without saying that desexing reduces the number of unplanned and unwanted litters.

But does that mean state governments should introduce legislation to make desexing compulsory? Both the Australian Veterinary Association (AVA) and Pets Australia say “no”.

“Virtually every veterinarian in Australia supports desexing, but the AVA is not in favour of mandatory desexing and Pets Australia members have similar views,” Dr Sillince says.

“The real problem comes from breeders and owners who ignore current laws. Putting a new law in place won’t stop these people simply ignoring it, so mandatory desexing isn’t a sure-fire way to reduce the number of unwanted dogs in shelters and pounds.”

She adds that mandatory desexing has failed in areas where it has been tried. Dr Sillince also argues that it would be unenforceable because local councils don’t have the resources to police such laws.

“What will reduce the number of shelter dogs is better tenancy and strata laws that allow pets, stopping the dumping of animals just because the owners can’t find a landlord that will let them keep them,” she says.

“We also need more positive incentives around microchipping and different pound and shelter systems that avoid the need for people to have their impounded pets put down because they can’t pay the recovery fee.”

More information

To find out more about desexing your dog, including a list of veterinarians who will desex your pet at a reduced fee, visit the National Desexing Network’s website at

Want more articles like this? Subscribe to Dogs Life Magazine

You need to look after your pooch's health - check out our all-new DOGSLife Directory

Got Something To Say:

2 Responses to Should you desex your dog? What you need to know about desexing

  1. If I desex my female will she stop trying to hump my male

  2. Under “The case against desexing” in this article, you don’t mention any of the real arguments against desexing – such as the links between early desexing and abnormal bone growth, bone cancers, endocrine diseases, shorter life span et.c. found in breed-specific research studies (albeit the studies done are breed-specific, there is no reason to think the problems don’t apply to all breeds). Read Mercola Vet/Dr. Becker’s article about it – she isn’t the only one to raise caution about early desexing but her article is an easy read.

    I think that a decade or two down the track we’ll see huge backlashes of the massive desexing blanket-campaigns taking place now and the tides turning against blanket recommendations to desex, not because early desexing is always a bad idea, but because it takes place on such an unnecessarily massive scale today, being preached almost religiously to all pet owners (regardless whether it is necessary in their case or not) – it is bound to cause epidemic-scale health issues down the track. It would be better to be less religious about it now, take the health risks into account, and in each case weigh potential benefits against potential disadvantages, rather than desex everything.

    In our case, the desexing is totally unnecessary. We’ve got a secure yard and are responsible, experienced dog owners. We’d rather have avoided that our dogs had such a major invasive surgery early in their lives if we’d had a choice – but we didn’t (buying rescue dogs). They are both rescues from different backgrounds and diff breed mixes, females, 3yo, both desexed as young puppies. They both have (different) joint issues that means that none of them can really keep up with what we consider normal daily exercise activities. We love our dogs as they are. However, in our preliminary considerations about perhaps getting a third dog as a running buddy for me (none of our dogs are up for the job on a daily basis because of joint issues) one of our health criteria for the potential third dog (beyond good fitness and sound conformity) is that he hasn’t been desexed before fully mature (~ 3yo, preferably older), and intact is OK too.