10/28/2025
The science behind early spay and neuter. It matters.
*Preventing unwanted litters is a goal we all share—but it's time to rethink the surgical approach. Hysterectomies and vasectomies, which preserve hormonal balance, can safely be performed as early as 8 weeks of age, making dogs sterile without disrupting their natural hormones.
New peer-reviewed study published in Nature:
How a dog’s lifetime exposure to his own hormones (before being neutered) affects how well he handles aging and frailty later in life.
Study Background
• Frailty = when older dogs (and people) become weaker, less resilient, and more prone to illness and death.
• Most research looks at how to prevent frailty — this study looked at what makes some dogs bounce back better after frailty sets in.
• The focus was on the HPG axis — the hormonal system that produces testosterone and controls reproduction.
Key Findings
• Dogs neutered very young (before 2 years old) had:
o A much higher risk of death once they became frail.
o About 16% higher mortality for every small increase in frailty.
• Dogs kept intact longer (more than ~10 years) showed:
o No increase in mortality linked to frailty.
o Their hormones seemed to “buffer” the negative effects of aging.
• Each extra year of natural hormone exposure reduced frailty-related death risk by ~1%.
What It Means
• Hormones from the te**es may protect against the worst effects of aging later in life.
• Removing them too early could make dogs less resilient to age-related decline.
• Frailty isn’t just about getting old — it’s also shaped by early-life events like the timing of neutering.
• This supports a “life course” view: what happens early in life affects health decades later.
Why It Matters
• The study suggests timing of neutering might influence how well dogs age.
