07/31/2026
DOES SPAYING OR NEUTERING REALLY MAKE DOGS CALMER?
For decades, many people have been told that spaying or neutering helps reduce unwanted behaviors. But a new 2026 peer-reviewed review published in Animal Reproduction suggests the science is more complicated.
After reviewing decades of research, the authors concluded there’s not enough consistent evidence to recommend spaying or neutering solely to change behavior. In fact, several studies included in the review found some dogs showed more fear, anxiety, or certain forms of aggression after being spayed or neutered.
Why? The review explains that reproductive hormones don’t just influence reproduction. They also play important roles in brain function, learning, memory, stress responses, and emotional regulation. Removing those hormones may affect dogs differently depending on their genetics, age, s*x, breed, and individual temperament.
One of the most interesting parts of the review is that the authors discuss hormone-preserving alternatives that prevent breeding while allowing the body to continue producing its natural hormones. These include:
🐕 Vasectomy – prevents male dogs from reproducing while leaving the testicles in place, so testosterone production continues.
🐕 Ovary-sparing spay – removes the uterus but leaves one or both ovaries intact, preventing pregnancy while preserving ovarian hormone production.
The authors suggest they deserve more attention because they can help preserve some of the health and behavioral benefits associated with natural hormones while still preventing unwanted litters.
The review doesn’t argue that dogs should or shouldn’t be spayed or neutered. Instead, it encourages veterinarians and pet owners to move away from a one-size-fits-all approach and make decisions based on each dog’s individual health, lifestyle, behavior, and risk of reproduction.
