Just the word 'castration' strikes fear in the heart (and groin) of chaps everywhere

But think of it this way, you're freeing your dog from the hormones that make him act like an idiot and get him (and you) into trouble. 

We don't just recommend castration to control breeding, we recommend it because dogs without testosterone factories (ie testicles) make better pets.

Trust us, testosterone is no friend of the family pooch.

The downside of testosterone

Testosterone is responsible for the development of behavioural patterns such as:

  • Aggression – hormone surges can make your dog do things like have a go at or hump other dogs, both potentially resulting in a punch on. Even when there are no surges, other dogs can detect the pheromones given off by an entire male dog and may go on the attack – no matter how sweet natured your boy is. Intact dogs are more than twice as likely to be bitten by another animal as neutered dogs. How much castration suppresses aggression varies between dogs and the age it's done.
  • Roaming – the pheromones given off by female dogs in heat travel great distances in the air and act like a powerful magnet for entire male dogs. This can lead to dogs escaping and getting picked up by the pound or hit by a car – intact dogs are twice as likely to be hit by a car as neutered dogs. If your dog can't escape then he is essentially sexually frustrated until the pheromones go away. Dogs who are castrated at around 6 months of age do not sense or respond to pheromones and are happy to stay at home.
  • Distraction - entire males are easily distracted and make poor students during training and stubborn ignorers of your calls at the park.

Testosterone has medical consequences too, including:

  • Prostate disease – over 80% of entire male dogs develop prostate disease such as enlargement, infection, cysts and cancer.
  • Perianal tumours – which grow around the anus due to testosterone stimulation and can be very nasty.
  • Perineal hernias – which are protrusions of abdominal organs through the muscle wall around the anus. Testosterone can weaken the muscles allowing the colon, bladder, prostate and fat to slip through creating a bulge beside the anus. This is uncomfortable and may even stop your dog from being able to urinate or pass faeces. Perineal hernias need to be repaired surgically.

And now for balance...

The up side

Testosterone is an anabolic steroid hormone, and along with other hormones (like Growth hormone), it promotes muscle development. There is limited evidence that early castration (before 6 months) of some larger breed dogs (eg Golden Retrievers and German Shepherds) may be associated with joint issues (such as cruciate disease) and with some cancers.

Now, this doesn't mean that these breeds shouldn't be castrated. But it does suggest the timing of castration may have extra significance for some dogs.

We don't do the sorts of early neutering done at some shelters and by some breeders. For most of the breeds that we see, castration between 6 and 12 months is appropriate. We can weigh up the benefits and risks for your pet and create an individual plan.

So now you understand the why of castration, let's take a look at what is involved.

Okay, let's do this!

Okay, let's do this!

Castration – the not so scary procedure

If you want to know what's involved, read through each step. If you feel ignorance is bliss in this matter, skip to 'Recovery'. If it's all too much, scroll down to an alternative to surgical castration.

At home

There's not much you need to do to prepare for surgery. Just make sure he has no food after midnight (water is okay) because he needs to be fasted for an anaesthetic. During anaesthesia, sphincters relax and protective reflexes stop working. This increases the risk of stomach contents refluxing up (through the lower oesophageal sphincter) into the throat and going down the windpipe.  


Admission is usually between 8 am and 9 am, but if this doesn't work for you, let us know and we can work something out. If we haven't seen your dog before then he needs an admission appointment with a vet, otherwise he is simply admitted by one of our nurses. 

You'll need to fill out a consent form when you arrive. This basically outlines:

  • what's going to be done – not just the castration but things like nail clips, microchipping, baby teeth removal, ear cleaning if you would like it done
  • our responsibilities – providing your dog with best practice care, including safe anaesthetic techniques and good pain management
  • your responsibilities – having a number we can reach you on and paying the bill when you come to pick him up

If you want, you can schedule a discharge appointment for the afternoon now. Otherwise, you can do this when we call to say he's ready.

Ward time

After admission, your dog will be settled into a comfy cage by his nurse for the day, where she'll check his heart rate etc.

About 30 minutes before surgery, he will be give a 'pre-med'. The exact medications in the pre-med are tailored for each patient, but it will contain a sedative to help him feel nice and relaxed. Dogs that are very anxious can be given their 'pre-med' early.

Anaesthetic induction

When it's time for surgery, your dog will be taken to the 'prep' area near the operating theatre. He will have a bit of fur clipped from one of his front legs and an IV line will be placed. This line provides IV fluids throughout the procedure.

The vet will inject an anaesthetic through the IV line and your dog will drop off to sleep... this is the last thing he'll remember until he wakes up after the op.

Once he's asleep, a tube will be placed into his windpipe and then connected to an anaesthetic machine that supplies him with oxygen and inhaled anaesthetic to keep him asleep. Monitoring equipment continuously measures his heart rate, oxygen level, blood pressure and breathing and his nurse charts the readings.

Surgical prep

The surgery nurse will now prepare his downstairs area for surgery, this means shaving some fur from around his scrotum and then doing a special multi-step cleaning process.

While your dog is being prepared for surgery, the vet is also going through a prep process. This involves putting on a surgical cap and mask, scrubbing up hands and arms, donning a sterile gown and then putting on sterile gloves – once these are on, we only touch sterile objects.


Once the surgery prep is complete, your dog will be carried into the theatre. There he'll be placed on his back on a nice warm pad.

The vet will place some sterile drapes over the surgical site to keep the surgical field clean and clear. The instruments are then unwrapped and set up ready for surgery.

The vet makes a small incision just in front of the scrotum – both testicles are removed through this one incision (one at a time!) The blood vessels and sperm ducts supply each testicle are securely tied.

The vet will then close the incision with a couple of layers of stitches – one in the fat and connective tissue under the skin and the other in the skin. Sometimes the skin stitches are visible (and need to be removed) and sometimes they're invisible (and will dissolve). 

Before we turn off the anaesthetic, your dog be given some pain relief so he'll be comfortable when he wakes up.

If you've said you want it, we'll tattoo his ear (note: it's not a cool tattoo).

Once the anaesthetic gas is turned off, your dog will breathe oxygen until he starts to wake up.

When he can can swallow, the tube is taken out of his windpipe. He'll then be carried back to his hospital bed, where his nurse will stay with him until he's fully awake and will then remove his IV line.

Once he's had a chance to relax and recover, he'll be taken out for a wee and offered a light lunch.


Home time!


At your discharge appointment, we'll go through the post-op instructions, which are:

  • try not to let him run around for the first week – running and jumping can 'stretch' the surgery site and lead to swelling
  • don't get the surgery site wet until the stitches are out (or for 10 days if there are no visible stitches)
  • don't let him lick at the area, this can cause the skin to become very angry and possibly even cause infection (no, dog's tongues and saliva are not good for wounds). This may involve the dreaded bucket on the head
  • give the pain relief provided (instructions will be on the packet)

Then you just need to make an appointment for a post-op check (+/- stitch removal) and you're done!


Is there an alternative to surgical castration?

Yes. We can do chemical castration. The most common form used currently is an implant (Suprelorin®) containing a hormone that suppresses testosterone and fertility. There are two strengths, with the lower one lasting around 6 months and the high strength one lasting 12 months. 

The main reasons we do chemical castration are:

  • the dog is going to be used for breeding later on (please be realistic about this option for your pet dog – as great as your dog is, there may not be a huge demand out there for your dog's semen)
  • we're trialling the effect of castration on behaviour before considering surgical castration
  • we're treating prostate or other testosterone-related disease in a dog that might be too old or too sick for surgery

Occasionally, some people are really attached to their dog's balls and can't bear to see them go. So then chemical castration is basically used for cosmetic effect... although, finding a full scrotum on a dog attractive is kinda niche.


If you want more information, give us a call on 9531 1771