Do Dogs Have Testosterone? The Good and The Bad

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Written by: Celestine Gomez
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Just like us, dogs have several glands in their bodies that produce hormones. These hormones affect everything in the dog’s body, from its growth to behavior and sexual maturity.

But do dogs have testosterone? How does it affect them?

In this article, we’ll explain how testosterone affects your dog’s life, positively and negatively. So, keep reading to find out.

Do Dogs Have Testosterone?

Female and male dogs have testosterone produced in their bodies. As a matter of fact, testosterone affects male and female puppies when they’re still in the womb.

The hormone spreads from the amniotic membrane to reach the puppy’s brain, affecting its physical and mental development and showing typical masculine traits. This happens even if the pup is a female, as it gets affected by the testosterone delivered to her brothers.

Puppies sleeping in a pile

After birth, testosterone is produced by the adrenal gland in female and male puppies, but the testicles produce more testosterone in male puppies.

However, the amount produced in the female body is much less than that in the male body. For example, in male puppies, the amount is 2 mg/ml versus 0.1 mg/ml in females.

During this early stage of life, the effect of testosterone is minimal, and some male dogs might still retain their feminine traits. Despite being low, testosterone levels affect dogs’ behavior until maturity, when they receive a hormonal surge.

Male Dogs and Puberty

In addition to the initial difference between female and male dogs, male dogs receive a testosterone surge just before they reach maturity. This starts by the time the puppy is four to six months old, as the levels of testosterone start increasing.

The levels keep on increasing until they reach their maximum when the puppy is between six and 12 months old. The testosterone levels affect the male dog’s behavior, establishing its status as an adult male that is ready to mate.

They remain unchanged for five to six years and start declining by the time the dog is seven years old. These levels decline significantly when the dog becomes a senior.

How Does Testosterone Affect Male Dogs?

Testosterone intensifies the male behavioral patterns in male puppies and adolescent dogs. Its level can reach up to 4ng/ml in fertile adult male dogs. When they fall below 0.4ng/ml, the dog is considered infertile. Here are some ways testosterone can impact your dog’s behavior and health.

  • Testosterone levels are essential for bone growth. They also support your dog’s cardiovascular health. 
  • As the levels of testosterone increase, male dogs can become more competitive.
  • Testosterone can make timid dogs feel more confident. However, overly confident dogs can become too confident or even aggressive.
  • Dogs can become more persistent and determined.
  • Risk-taking behaviors during play and aggressive encounters with other dogs increase.
  • The male hormone can increase sexual-related behaviors. This includes sexually-based humping, marking, thrusting, and roaming. At a young age, a puppy might display some of these patterns, but they’re considered part of playing.
  • As the level of testosterone increases in adult dogs, urine marking behavior increases as the dog is marking its territory.

Should You Neuter Your Dog?

Castration, fixing, or neutering your dog is one of the most popular practices to control its behavior. This surgical procedure involves removing both testicles, thus preventing the dog from producing sperms and testosterone. After castration, your male dog will become infertile.

There are some benefits to castration, but it also comes with some downsides that you need to consider. Here are the pros and cons of this procedure.


  • After neutering, your dog will be unable to mate.
  • Neutering eliminates the risk of testicular cancer, which typically affects older dogs.
  • Because testosterone levels are significantly reduced, it decreases the risk of age-related prostate issues in senior dogs.
  • Territory marking or urinating is significantly reduced, especially if it is related to elevated testosterone levels.
  • Roaming and wandering to find a mate is reduced.
  • Testosterone-related competitive aggression with other dogs is reduced.
  • Humping and thrusting behaviors are reduced.


Right after the procedure, your dog might become more manic or reactive until it gets used to the change. This is because the pituitary gland is unaware that the testicles have been removed, so it continues to send signals to the body to produce testosterone.

  • Some dogs can become too fearful of other dogs after castration.
  • Fixed dogs are more prone to obesity.
  • Incontinence and osteoarthritis are more common in neutered dogs.
  • Fixed dogs are more likely to experience anxiety, fear, and depression.
  • Wandering and roaming because of boredom and lack of interaction or exercise won’t be solved if you fix your dog.
  • Castrated dogs will still chase prey and mark their area out of fear.

Due to the negative sides, some vets and pet owners consider medical castration, using medications instead of the surgical procedure. This procedure is reversible but can have the same positive impact on your dog’s behavior because it reduces the levels of testosterone.

Can Neutering Eliminate Aggression?

Two dogs fighting

Fixing or neutering your dog won’t eliminate aggressive behavior, as it’s usually related to another problem. In most cases, the levels of testosterone won’t be the reason behind your dog’s aggression, as this behavioral problem is present in female dogs as well.

Aggression is mainly related to socialization. Territorial or fear-reduced aggression won’t be solved if you fix your dog, but training and socialization will help alter your dog’s behavior. However, the reduced level of testosterone will help control your dog’s behavior and make it less reactive.

Final Thoughts

Testosterone is present in the bodies of female and male dogs, although the level of testosterone is significantly higher in male puppies. Testosterone is essential for your dog’s physical and mental development, and any change in its levels can affect its fertility and overall behavior and temperament.

A lot of people choose to neuter or fix their dogs to solve some health and behavioral issues. However, this procedure has several pros and cons that you need to consider and discuss with your vet before scheduling a surgery.

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Celestine Gomez

I'm Celestine Gomez, worked for 5 years in an animal shelter in Los Angeles, California. Having noticed the inherent passion and zeal in me to care for pets, I took a step further to create a team of I and like-minded individuals to provide an informative resource in order to broaden the knowledge base of a regular pet owners.