My dog needs de-sexing, what is involved?

23 Aug 2024

We understand that decisions around desexing your dog are complex. There are several pros and cons to de-sexing. Furthermore, there are several different procedures that can render your dog sterile and these have their own set of pros and cons.

Below is a summary of the recent literature surrounding the advantages and disadvantages of de-sexing provided by Dr
Abbie Tipler ATCL BVSc MANZCVS FANZCVS -Small Animal Surgical Specialist. from Veterinary Specialist Services (VSS), Brisbane, Australia
(www.drabbietipler.com). Please note that this information may change over time as new research emerges.

This pros and cons list should be interpreted in light of the disease prevalence, which can vary based on breed and region. 

Therefore, although this gives an overview we recommend booking a consultation with one of our vets to discuss how this information may apply to your dog and enable us to make a recommendation specific for your dog and situation.

Pros of Desexing

Males

• Castration reduces the risk of testicular tumours.

• Castration reduces the risk of benign prostatic neoplasia, chronic prostatitis, perianal adenomas and perianal hernias.

Females

 • Ovariohysterectomy may reduce the risk of mammary cancer. The reduction in risk seems to be small and some breeds are more prone to mammary cancer than others.

• Ovariohysterectomy reduces the risk of ovarian neoplasia, uterine neoplasia and vaginal tumours.

 • Ovariohysterectomy prevents pyometra, metritis and ovarian cysts as well as problems associated with pregnancy and parturition. Some breeds are more prone to pyometra.

Males and Females

• Desexing has been associated with an overall increase in life span, due to decreased mortality associated with trauma and infectious disease, in some studies.

• Desexing reduces the risk of transmissible venereal tumours, a sexually transmitted disease.

Cons of Desexing

Males

• There is an increased risk of prostatic carcinoma.

Females

• There is an increased risk of urinary incontinence in some breeds. This problem affects around 6-9% of neutered females and larger breeds are more prone to this.

Male and Female

• There is an increased risk of obesity.

• There is an increased risk of joint disease if desexed prior to skeletal maturity (for example cruciate ligament disease, elbow dysplasia and hip dysplasia) in some breeds, especially larger breeds when desexing is performed prior to skeletal maturity (see below for breed specific information).

 • There is an increased risk of cancers in some breeds. The risk is sometimes reduced when desexing is performed beyond a certain age. These factors (i.e. risk and age at desex) vary between breeds (see below for breed specific information).

Behaviour

The hormonal effects on behaviour are more complex than once believed. There is some evidence that the longer dogs are exposed to hormones, the lower the risk of some behavioural problems. Desexing does seem to reduce some problem behaviours such as roaming, hormonal interdog aggression and urine marking. It possibly increases aggressive behaviours, and this is more common in puppies already demonstrating fearful or aggressive behaviours. Studies have revealed that the most serious human dog bite injuries have involved intact dogs. In some regions however, desexing is linked to better overall husbandry and therefore the effect of desexing specifically, can be difficult to determine.

Breed Specific Considerations

The pros and cons of desexing can vary by breed. There have been some breeds that have been studied in more detail. For breeds not specifically listed, similar breeds may exist to provide a guideline.

A good summary of the risk factors for various diseases by breed can be found by accessing the article ‘Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence’ by Hart et al. https://www.frontiersin.org/articles/10.3389/fvets.2020.00388/full

There is a similarly good article examining mixed breeds.

https://internal-journal.frontiersin.org/articles/10.3389/fvets.2020.00472/full

The take home message from this article, is that mixed breeds >20kg adult body weight, have an increased risk of joint disorders when desexed prior to 12 months of age. There is no increased risk of cancers in the desexed mixed-breed population of any size category. Be mindful these articles do not consider the risks associated with trauma, sexually transmitted disease, obesity or behaviour and they do not consider overall lifespan. 

Options for Sterilisation of Dogs

Females

Ovariohysterectomy

• This is the traditional procedure, and the ovaries and part of the uterus are removed.

• Hormones are not maintained due to the ovaries being removed.

• Dogs will not have a heat cycle.

• Unless part of the ovary is accidentally left (called iatrogenic ovarian remnant syndrome), they are not able to develop pyometra because the hormonal effect on the uterus is lost.

Ovary-Sparing Hysterectomy

• This procedure removes the uterus, cervix and possibly one ovary.

• Because at least one ovary remains, hormones are maintained as are their potential protective effects on some diseases.

• The dog will have a heat cycle and may have a very small amount of bloody discharge. They will be attractive to other dogs and may exhibit undesirable behaviours of being on heat such as yowling and the desire to mate.

• They are infertile and unable to get a pyometra, unless part of the uterine tissue remains and then the patient can develop a stump pyometra, which requires further surgery.

• They can develop ovarian neoplasia, but this is fairly rare.

• Because this is a relatively new procedure, there is not a lot of information in the literature regarding complications, and unanticipated complications may therefore occur.

• A much bigger surgical incision needs to be made for this procedure and the surgery is more complex making this a more costly procedure to perform.

Tubal Ligation (Salpingectomy)

• Tubal ligation removes a portion of the oviducts but leaves the ovaries, uterus and cervix.

• Hormones are maintained and the dog still experiences a heat cycle. They will be attractive to other dogs, may have bloody discharge during the heat cycle and may exhibit undesirable behaviours of being on heat such as yowling and the desire to mate.

• They are infertile but able to get a pyometra and uterine/ovarian neoplasia. For these reasons, it is generally not recommended.

Ovariectomy

• Removes the ovaries but preserves the uterus and cervix.

• Hormones are not maintained due to the ovaries being removed.

• They are infertile.

• Unless part of the ovary is accidentally left (called iatrogenic ovarian remnant syndrome), they are not able to develop pyometra because the hormonal effect on the uterus is lost. Note: This procedure is very similar to the traditional ovariohysterectomy in terms of the expected outcome.

Males

Traditional castration - removes the hormones.

Vasectomy - preserves the hormones.

Further Details

Because operations are performed under general anaesthetic your dog will need to spend the day with us and will need to be fasted (no food after 8.00pm in the evening the night before and no breakfast in the morning, water should be taken away at 7.00am).

The vet will perform a pre-operative health check on the morning of the surgery to check that your dog is fit and well, and in good shape to undergo an anesthetic and surgery. We will phone you if there are any concerns. Two to three days after the operation we schedule another appointment with you to make sure everything is okay and that your dog is recovering well.  A final appointment is required after approximately ten days to remove the stitches.

At Vetcall the price includes the pre-operative health check on the morning of the surgery, post-operative check 2-3 days later and stitch removal, short acting potent painkiller (6-8 hours effect) and 24 hour anti-inflammatory painkiller injections given at the time of your dog’s surgery and 2 days of anti-inflammatory painkiller tablets to take home.

We only use modern safe anaesthetic drugs, and all anaesthetics are monitored by a qualified veterinary nurse.

You have the option to have a pre-anaesthetic blood test performed as well as having your dog put on intravenous fluids (fluid drip).

A pre-anaesthetic blood test is performed on the day of surgery and gives us valuable information and peace of mind.  A small sample of blood is collected and tested to check if your dog’s organs are functioning normally, and helps to reveal any hidden conditions.  This helps us select the best anaesthetic protocol for your dog and minimise risks and consequences. 

Intravenous fluid support given throughout your dog's operation and recovery period reduces risk by helping to maintain a normal blood pressure and ensures immediate access to your dog’s circulation should any anaesthetic or surgical complications arise. Dogs supported with intravenous fluids have a quicker smoother recovery and less post – operative complications.