Thinking of Neutering Your Male Dog? Test Before You Neuter
Surgical castration (canine neuter / dog neutering) is needed to prevent progeny in the herd or to control hypersexual behaviour of your male dog. It is permanent and not always the answer to the unwanted behaviour of your male dog. A dog treatment can let you see what neutering surgery can result into — before you commit.
KNOW YOUR MALE DOG
The Basics
- Sexual maturity: 6–12 months (up to 2 years in large breeds)
- Fertile year-round — no heat cycle, always ready to breed
- Strongly driven by pheromones from females in heat
- Can "tie" with a female for 5–60 minutes during dog breeding mount
- Fertility can persist for life, though it may decline with age
COMMON MYTHS Regarding Neutering
Don't Let These Stop You
He's too old.
Age is rarely a barrier. Your vet assesses health — not birthdays.
His personality will change.
Hormone-driven behaviours may be reduced. His core character won't.
He'll get fat.
Diet and exercise drive weight, not male dog neuter procedures. It can be managed by testing before dog neutering.
BEHAVIOUR — KNOW THE DIFFERENCE
Is It Testosterone, or Something Else?
Before acting, understand what's actually behind the unwanted behaviour.
Testosterone-Driven
- Excessive Urine marking
- Canine humping — dog humping a toy, excessive mounting
- Running away from home after a female dog
Not Always Testosterone
- Aggressive barking dog behaviour — mostly shaped by environment and socialisation
- Dog barking — including dog barking at night for no reason — often a training issue, not a hormonal one
- Lack of self-control — a training issue, not a hormonal one
Note: Dog neutering / male dog spay procedures can improve or worsen aggression. Always consult a canine vet or dog veterinarian near me before acting on aggressive dogs.
THE APPROACH
Four Steps. One Smart Decision.
1. Identify
Is it hormones, behaviour, or both? Your dog vet near me or behaviourist will know.
2. Test
A reversible implant mimics surgical castration — temporarily. This dog treatment lets you watch what changes for the next few months after the implant.
3. Observe
Did the problem reduce? Worsen? Stay the same? Now you have real data.
4. Decide
Make the permanent call with evidence from your own dog, not guesswork.
Talk to your vet about a Test Before you Neuter.
Always consult your veterinarian before making medical decisions for your pet.
What is there in the Contraceptive Implant?
The implant releases a substance called deslorelin acetate. This active ingredient resembles the body's own hormone named 'Gonadotropin-releasing Hormone' (GnRH), but has a slightly different effect. Deslorelin Acetate is a GnRH agonist.
What does the implant look like?
The implant measures around 12.5 mm long and 2.3 mm thick. Ask your veterinarian to show the implant.
How does the implant work?
The continuous release of deslorelin acetate from the implant blocks production of the sex hormone testosterone. The lack of testosterone means that sperm cannot be produced and results in infertility.
What is a Reversible Contraceptive Implant?
Reversible Contraceptive Implant involves placing a 4.7 mg implant under the skin to cause a temporary suppression of testosterone levels that leads to infertility. This is a form of dog sterilization without permanent surgery.
What dogs can benefit from the Contraceptive Implant?
This dog treatment can be considered for healthy, intact, sexually mature male dogs of any breed or size — both testicles need to be descended into the scrotum.
Why should I consider Reversible Contraceptive Implant?
It provides an opportunity to learn what effects castration has on your dog. For example, will dog humping behaviour or other testosterone-driven conduct change? If satisfied with the effects, you can either continue with reimplantation every six months or consider the permanent solution of dog spay and neuter surgery. If concerned about general anaesthesia, repeated implantation may provide the solution. It also helps you evaluate the cost to spay or neuter a dog versus ongoing implant treatments.
How long does the implant last?
The duration of infertility is a minimum of six months from the date of implantation, although it can vary between individual patients.
Does this implant need to be removed?
This implant is biodegradable and will break down over time. It does not need to be removed.
How long does it take for the implant to be effective?
Infertility is NOT immediate. Infertility is achieved six weeks after implantation.
Are there changes in nutritional needs after implantation?
As with any dog sterilization procedure, your dog's diet should be adapted to avoid weight gain from the metabolic changes that result from castration. After castration, your dog's daily energy needs may decrease by 30% but your dog may want to eat up to 60% more. This imbalance means that your dog is at two times the risk of becoming obese. Diets specifically formulated for the needs of spayed and neutered pets are available from your veterinarian. Virbac's Veterinary HPM pet food, with its high protein (90% animal-sourced), low-carb formula, supports ideal body weight.
Does implantation produce any painful reaction?
Mild redness and swelling may occur in the implantation area within the first few days after application. However, these reactions are rare and heal without problems. Consult your canine vet if your dog shows more severe reactions.
What can I expect after the implant becomes effective?
When testosterone disappears, male behaviours — including dog humping and canine humping — will reduce or disappear. It is important to remember that behaviour problems are not always related to testosterone, and neutering surgery will not eliminate all unwanted behaviours. Due to the decrease in testosterone, no new sperm will be produced, so the dog will be infertile while the implant is having its effect. A clearly visible change after medical castration is that the testicles are smaller (on average, 30% smaller). Knowing how to stop a dog from humping often starts with this kind of hormonal assessment.
How can I monitor my dog's response to the implant?
Following implantation, your dog can be monitored for a reduction in testicle size. Size decreases by approximately 1/3 and may be seen by six weeks. Very occasionally an implant may fall out. If you are concerned that your dog has not responded to the implant, a blood test to measure testosterone levels may be taken six weeks after implantation. If you think your dog may not be responding to the implant, please contact your dog veterinarian near me.
Is the reversible contraceptive safe?
Reversible Contraceptive Implant has been routinely used to medically castrate male dogs around the world for almost 20 years. There are no significant side effects. Soreness at the implantation site is rarely seen. It remains a proven dog treatment and a safer first step before committing to male dog neuter surgery.
What happens during the first 6 weeks?
During the first six weeks, your male dog is still fertile and should be kept away from intact female dogs. Prior to the reduction of testosterone levels, there is a short-term stimulation of hormone production, which will initially temporarily increase the testosterone concentration in the blood. Stimulation can occur within 1–2 hours after implant administration. This means testosterone-related behaviours — including dog humping a toy or dog barking — may increase. For most dogs, this increase is not noticeable. After 1–2 weeks, the testosterone levels start to drop below detectable levels. In the following 3–4 weeks, testosterone continues to drop, no new sperm are being produced, and the male dog needs to clear the sperm he has already made and is storing in his epididymis.
When will the implant need to be renewed?
The duration of infertility is a minimum of six months from the date of implantation, although it can vary between individual patients. It is recommended to reimplant every six months to maintain the implant's effect — or consider neutering male dog surgery, if appropriate for your dog. The dog spay neuter cost and cost of dog sterilization should be discussed with your dog vet near me or through spay services near me to find the best option. Once the implant begins to lose its effect, your dog's testicles will begin to resume their usual size and sexual behaviour will start to go back to normal. Reimplantation every six months should prevent this from occurring.
Always consult your veterinarian before making any medical decisions for your pet. For dog vaccinations, dog diseases, and other health concerns, reach out to a qualified canine vet or search for a dog veterinarian near me.