De-sexing Dogs: A Deep Dive into the Behavioral and Developmental Impacts

In my role as the Lead Canine Behaviour Specialist at Noble Canine, I am frequently asked to address concerns about de-sexing, especially in the context of rescue and puppy mill dogs.

This topic is layered with complexities regarding the timing of the procedure and its effects on a dog's behavior and overall development. This article aims to provide an in-depth exploration of these aspects, offering insights for dog owners navigating this decision.

Understanding the Timing of De-sexing

• Early De-sexing and Its Developmental Impacts: De-sexing, which refers to the surgical removal of reproductive organs in dogs, has traditionally been performed at around six months of age. However, research from the University of California showed that early desexing of dogs can have health and psychological impacts. As such it is now advised that the age be nine months for toy breeds, and twelve to eighteen months for large or giant breeds.

The Behavioural Implications of Hormonal Alteration

The hormonal changes resulting from early de-sexing can significantly impact a dog's behavior. Some of the critical hormones affected by this process are testosterone, oxytocin and vasopressin, both of which play substantial roles in shaping canine social behaviours and aggression.

• Testosterone and Behavioural Development: Testosterone and other sex hormones play a pivotal role in shaping a dog's behavior. Studies as published by the Veterinary Journal 197, indicate that dogs de-sexed later in life, thus having increased lifetime exposure to sex hormones, exhibit fewer behavioural issues such as persistent barking, fear, and anxiety in response to stimuli like loud noises. In contrast, dogs de-sexed early may display more instances of fear and anxiety. Testosterone plays a vital role in developing confidence and behavior. Dogs with prolonged exposure to their natural sex hormones, usually due to later de-sexing, exhibit fewer behavioural problems. They display a natural boldness and reduced fear and anxiety compared to those de-sexed early. This aspect is particularly significant for dogs from rescue or puppy mill backgrounds, who often exhibit anxious or reactive behavior. The presence of natural hormones can help in developing more stable and confident temperaments.

• Oxytocin's Role: Often dubbed the 'love hormone', oxytocin is associated with bonding, social interaction, and calmness in dogs. A study in "Frontiers in Psychology" found higher levels of oxytocin in service dogs, which are known for their serene and sociable temperaments. This suggests that oxytocin may contribute to more amiable and less aggressive behavior in dogs.

• Vasopressin and Aggression: The same study revealed that dogs displaying more aggressive tendencies towards other dogs had elevated levels of vasopressin. This hormone, contrasting oxytocin, is linked with more aggressive social behaviors. Therefore, vasopressin levels could be a crucial factor in managing aggression in dogs.

Timing and Aggression: A Complex Relationship

• De-sexing and Aggressive Behavior: While recent reports suggest that de-sexing does not significantly alter aggressive behavior towards familiar people or strangers, the broader impact on aggression and temperament is nuanced. The procedure can be beneficial in managing certain types of aggressive behaviours, but its effects vary depending on the individual dog and its environment​​, in particular dogs who suffer from higher levels of anxiety and fear are more likely to react to potential triggers. Although both have the potential result of aggressive behaviour, it is important to understand the difference between aggression and reactivity.

Health vs. Behavioural Development: A Balancing Act

• Reduced Problem Behaviours vs. Increased Anxiety: While early de-sexing may lower certain behaviours like urine marking or howling when alone, it has been linked to an increased incidence of fear, anxiety, and less sociable behavior. This trade-off highlights the importance of carefully considering the timing of de-sexing, particularly in the context of a dog's overall behavioural health and development.

Mandatory De-sexing in Adoptions

• Benefits of Adoption Policies: The beneficial effects of mandatory desexing for adopted dogs welfare is underpinned by the need to reduce the number of unwanted companion animals. The requirement to desex actually saves the lives of many animals worldwide.

• Navigating Adoption Policies: Mandatory de-sexing policies in adoptions can pose challenges for the healthy and behavioural development of the dogs. If early de-sexing is advised, it is prudent to consult with a behavior specialist and veterinarian. As those who run the welfare organisations want what is best for the dogs, in some cases, an extension for the procedure may be approved if beneficial for the dog's developmental needs.

Rehabilitation Prospects for Affected Dogs

• Rehabilitation and Adoption: Anxiety or aggression issues in dogs, whether exacerbated by early de-sexing or not, can be addressed through behavioural rehabilitation and training. Although this journey is not necessary an easy one, these challenges should not deter potential adopters, as many such dogs can thrive in a nurturing environment.

Concluding Thoughts

Making decisions about de-sexing involves careful deliberation of the dog's welfare, behavioural health, and physical well-being. At Noble Canine, we encourage owners to make informed, individualised decisions, in consultation with veterinary and behavioural professionals. Prioritising the dog's welfare ensures a more fulfilling and happy life for both the dog and its owner.