Thinking of Neutering Your Male Dog? Test Before You Neuter
Surgical castration 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 test can let you see what neutering 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 mating
- 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 neutering. It can be managed by testing before 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
- Hypersexuality — excessive mounting, humping,
- Running away from home after female dog
Not Always Testosterone
- Aggression — mostly shaped by environment and socialisation
- Lack of self-control — a training issue, not a hormonal one
Note: Neutering can improve or worsen aggression. Always consult a veterinarian before acting on aggressive dogs.
THE APPROACH
Four Steps. One Smart Decision.
1. Identify
Is it hormones, behaviour, or both? Your vet or behaviourist will know.
2. Test
A reversible implant mimics surgical castration — temporarily. Watch what changes for the next few months after 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 Contraceptive Implant?
The implant releases a substance, called deslorelin acetate. This active ingredient resembles the body's own hormone names ’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 deslore-lin acetate from the implant blocks production of the sex hormone testosterone. The lack of testoster-one means that sperm cannot be produced and results in infertility.
What is Reversible Contraceptive Implant?
Reversible Contraceptive Implant invloves placing a 4.7 mg implant under the skin to cause as tempo-rary suppression of testosterone levels that leads to infertility.
What dogs can benefit from Contraceptive implant?
This 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 your dog's behavior change? If satisfied with the effects of Contraceptive implant, you can either continue with reimplantation every six months or consider the permanent solution of surgical castration. If concerned about general anesthesia, repeated Contraceptive implant may provide the solution.
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. Infer-tility is achieved six weeks after implantation.
Are there changes in nutritional needs, after implantation?
As with any neutering procedure, your dog's diet should be adapted to avoid weight gain from the metabolic changes that result from the 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 neu-tered 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 veterinarian if your dog shows more severe reactions.
What can I expect after the implant becomes effective?
When testosterone disappears, male behaviors will reduce or disappear. It is important to remember that behavior problems are not always related to testosterone and castration will not eliminate all unwanted behaviors. 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).
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 implan-tation. If you think your dog may not be responding to the implant, please contact your veterinarian.
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.
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 reduction of testos-terone levels, there is a short-term stimulation of hormone production, which will initially temporarily increase the testosterone concen-tration in the blood. Stimulation can occur within 1-2 hours after implant adminis-tration. This means testosterone-related behaviors 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 mini-mum 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 surgical castration, if appropriate for your dog. Once the implant begins to lose its effect, your dog's testicles will begin to resume their usual size and sexual behavior will start to go back to normal. Reimplantation every six months should prevent this from occurring.