Spaying and Neutering: A Balanced Look at the Benefits and Risks

For decades, spaying and neutering have been widely promoted as the responsible choice for dog owners. These procedures have played a major role in reducing unwanted litters and shelter overcrowding. However, as veterinary research continues to evolve, we are learning that the decision is more complex than it once seemed.

As a dog professional who cares deeply about long-term health and well-being of the dogs we work with and the Personal Protection dogs we sell,  we believe it is important for owners to understand both the benefits and the potential risks before making this permanent decision. 

The Benefits of Spaying and Neutering

There is no denying that spaying and neutering may offer some advantages:

Prevention of accidental litters- whether it be a stray dog roaming, the neighbors intact dog, or your multi-dog household– sterilization helps reduce the number of unwanted dogs and puppies entering shelters or rescues.

Reduction in certain cancers – Spaying eliminates the risk of uterine infections (pyometra) and reduces the risk of mammary cancer when done early. Neutering removes the risk of testicular cancer and reduces some prostate problems.

Behavioral benefits in some dogs – Neutering may decrease roaming, marking, and some hormone-driven behaviors.

However, for responsible owners who are able to properly manage intact dogs, accidental litters can often be avoided. At the same time, growing research suggests that the risks of certain aggressive cancers and orthopedic issues associated with early altering may outweigh the benefits of preventing mammary or testicular cancer alone.

In cases where a dog later develops testicular cancer or pyometra, spaying or neutering at that time would be medically appropriate to resolve the issue. 

Emerging Concerns About Long-Term Health

In recent years, multiple studies have raised important questions about the long-term health effects of early spaying and neutering. While research is ongoing, several consistent trends have emerged.

Joint and Orthopedic Issues

Dogs spayed or neutered at a young age may have an increased risk of:

* Hip dysplasia

* Cranial cruciate ligament (ACL/CCL) tears

* Elbow dysplasia

* Other orthopedic disorders

Sex hormones play an important role in growth plate closure and musculoskeletal development. Removing these hormones too early may affect proper joint formation, particularly in medium and large breeds.

Increased Risk of Certain Cancers

While spaying and neutering reduce some reproductive cancers, research suggests they may increase the risk of others, including:

* Osteosarcoma (bone cancer)

* Hemangiosarcoma

* Lymphoma

* Mast cell tumors

These cancers are often aggressive and life-threatening. Several studies indicate higher incidence rates in spayed and neutered dogs compared to intact dogs, especially when altered early in life.

Allergies and Immune-Related Conditions

Many veterinarians  have observed higher rates of:

* Environmental allergies

* Food sensitivities

* Skin disorders

* Autoimmune conditions

Hormones influence immune system regulation. Altering normal hormone levels may impact how the body responds to allergens and inflammation.

Behavior and Emotional Well-Being

Another important and often overlooked consideration is how spaying and neutering may affect behavior and emotional stability.

While it is commonly believed that altering automatically reduces aggression, research does not entirely agree. We have seen for many years, people spaying or neutering their dogs to reduce behavioral issues, and in fact, we have seen just the opposite. In our opinion the only behaviors that spaying/neutering will alleviate are prevention of inter household aggression among households with multiple intact females, and curbing dominant behavior. Very few dogs are truly “dominant” however and this would need to be done early on otherwise behavior becomes learned and neutering will not help.

Some studies and behavioral specialists have noted that neutered dogs may show increased fear-based or reactive behaviors, including:

* Anxiety

* Reactivity toward people or other dogs

* Defensive aggression

* Reduced confidence

Sex hormones play a role in confidence, resilience, and emotional regulation. Removing these hormones—especially at a young age—may contribute to insecurity, which can manifest as aggression or behavioral challenges. As a trainer that also specializes in behavioral rehabilitation of dogs, I can tell you that a very large portion of the dogs we “rehabilitate” are already neutered; many at a very young age. 

When Altering *May* Help Behavior

There are situations where neutering may be beneficial from a behavioral standpoint, including:

* Certain cases of hormone-driven dominance

* Inter-female aggression in multi-dog households

* Excessive roaming related to seeking mates

* Marking behaviors

In these specific contexts, altering can sometimes reduce conflict and tension.

However, for many dogs, especially those struggling with fear, anxiety, or poor social confidence, neutering does not resolve underlying behavioral issues and may, in some cases, make them worse.

Training Over Surgery

Behavior problems are most often rooted in:

* Genetics

* Early socialization

* Environment

* Training methods

* Past experiences

Surgery alone cannot replace proper training, structure, and behavioral support. Addressing behavior through professional guidance and positive training methods is far more effective than relying on neutering as a “fix.”

Weight Gain and Metabolic Changes

Spayed and neutered dogs often experience:

* Slower metabolism

* Increased appetite

* Greater risk of obesity

Obesity contributes to joint disease, heart problems, diabetes, and shortened lifespan, making weight management especially important for altered dogs.

One Size Does Not Fit All

Every dog is an individual. Breed, size, genetics, lifestyle, and environment all play major roles in health outcomes.

For example:

* Large and giant breeds may benefit from delaying spay/neuter until physical maturity.

* Working and sport dogs may require full hormonal development for optimal performance and durability.

* Dogs in high-risk breeding situations may benefit from earlier sterilization.

Blanket recommendations do not serve every dog and owner equally well.

Alternatives and Thoughtful Timing

For some owners, alternatives may be worth discussing with their veterinarian:

*Delayed spay/neuter – Waiting until growth plates close and maturity is reached.

*Vasectomy or ovary-sparing spay – Sterilization while preserving hormones (availability varies).

* Responsible intact ownership* – Preventing unwanted breeding through supervision and management.

These options require commitment, education, and responsible handling, but may offer long term health advantages in certain cases.

Making an Informed Decision

Spaying and neutering should not be viewed as an automatic decision, but rather an informed medical choice.

Owners should discuss:

* Breed-specific research

* Age and size considerations

* Lifestyle and activity level

* Family and community environment

* Ability to manage an intact dog responsibly

A knowledgeable veterinarian who stays current with research can help guide this conversation.

Our Philosophy

At Protection Dogs Plus, we believe in evidence-based, individualized care. Our goal is not to discourage responsible population control, but to encourage thoughtful decision-making that prioritizes each dog’s long-term health, soundness, and quality of life.

We support owners in learning, asking questions, and choosing what is truly best for their dog—rather than following outdated one-size-fits-all recommendations.

 Research and References

The following peer-reviewed studies and veterinary research have contributed to the growing understanding of spay/neuter timing and long-term health effects:

* Hart, B. L., Hart, L. A., Thigpen, A. P., & Willits, N. H. (2014–2020). *Long-term health effects of neutering in dogs: breed-specific analysis.* University of California, Davis.

* Torres de la Riva, G., et al. (2013). *Neutering dogs: effects on joint disorders and cancers in Golden Retrievers.* PLOS ONE.