Dog Breeding Trade Secret #10

Looking to avoid an unwanted dog pregnancy?

  • Unaware you could have your male chemically castrated? Or delay the female season?

  • Not clear what age to neuter or spay?

  • Want to know how soon after a season you should spay a bitch?

I only know of this hot tip because of my involvement in the show world. It isn't easy to show a neutered dog, so alternative considerations must be made. Likewise for owners that compete and work their dogs – as neutering can negatively impact behaviour and possibly hinder growth and development.

Let's look at how to avoid accidental mating’s and the essential proactive measures that should be taken by responsible owners. Regardless of age or biological connection, entire dogs will attempt to mate when one is in season due to natural hormone arousal and animal instinct.

Here are some steps you can take to prevent unplanned or accidental dog breeding:


Separation during seasons is essential if you have an intact female and male dog in the household, regardless of ages. She should be kept securely separated from intact males to prevent mating. All family members and visitors should be made aware of this restriction. Its preferable crates are used for the male and he is the dog that is caged, as a male can mate with a crated female. However, ideally, they should not be left in the same room at all, and both should be crated or separated by two doors at least.


Always closely supervise your dog when outdoors and interacting with other intact dogs. Prevent unsupervised access to other dogs, especially those of the opposite sex, to minimize the chances of unplanned mating’s. Females should not be exercised off-lead in public areas during their season’s time.

Spay or neutering

Having your dog spayed (females) or neutered (males) is one of the most effective ways to prevent accidental breeding. Spaying and neutering surgeries remove or render the reproductive organs non-functional, reducing the risk of unplanned pregnancies. Many owners typically delay spaying or neutering until physical maturity is reached at 18 months of age (or older) for the correct breed development to be attained.

Females should be neutered three months after their last seasons to avoid any impact on their heat cycle and to ensure a simplistic surgical procedure.

Chemical Castration

Temporary castration, also known as chemical castration, is a procedure in which a hormonal implant is used to inhibit the reproductive function of a male dog without permanently removing or altering the testicles (ideal for show dogs). It is considered a non-surgical alternative to traditional, surgical castration (neutering).

The procedure involves administering a medication via the implant (such as Suprelorin), typically containing a gonadotropin-releasing hormone (GnRH) agonist which suppresses the production and release of testosterone from the testicles. The reduction in testosterone levels leads to temporary window of infertility and a decrease in sexual behaviours.

Temporary castration can also be beneficial in certain situations, such as Behavioural Management to control unwanted sexual behaviours, including roaming, mounting, or aggressive behaviour. By reducing testosterone levels, temporary castration can help decrease such behaviours in certain instances making dogs more manageable.

In some cases, surgical castration may not be recommended due to underlying health conditions or age-related concerns. Temporary castration provides a reversible option for reproductive control, without permanently removing the testicles.

It’s important to note that chemical castration cannot guarantee the recovery of fertility once removed. So if the dog is to be used in your future breeding programme, semen should be collected and appropriately frozen by a canine reproduction specialist before proceeding with any type of castration.

Delay Heat

Suprelorin can also be used on females to delay the first oestrus and prevent young pregnancy in intact, immature female dogs. The implant should be administered between 12 and 16 weeks of age. This may be of consideration for certain competition dogs.

By taking these preventive measures, you can significantly reduce the risk of accidental dog breeding, unplanned puppies and contribute to responsible pet ownership. 

Need more advice?

If you've enjoyed this article and have any concerns or questions about preventing accidental breeding, more practical breeding advice and support await you inside the Canine Family Planner's™ Winners' Circle. During a bi-monthly "Breeders Brew" Support session, you can drain Sara's brain, road test her 25 years of dog breeding experience, and let her be your canine counsel to help you with your specific breeding problem and concerns.

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