Rethinking Spay & Neuter
- Dr. Andi Harper
- May 13
- 6 min read
Updated: May 19
What and When To Consider This Procedure For Your Pet
The Hormonal Symphony: Why Timing Matters
In the realm of canine health, hormones play a pivotal role. They influence not just reproduction but also growth, behavior, and overall well-being. Early spaying or neutering, while common, can disrupt this hormonal balance. Research from the AKC Canine Health Foundation indicates that delaying these procedures until after sexual maturity may offer long-term health benefits, including reduced risks of joint disorders and certain cancers.[1]
Bones, Joints, and the Growth Factor
You know those gangly, awkward teenage dog stages? That’s a growth phase powered by a delicate hormone dance. When we spay or neuter too early—before the sex hormones have finished their job—we interrupt that natural timing. Estrogen and testosterone aren’t just about reproduction. They play a critical role in signaling growth plates (those soft areas at the ends of bones) to close at the right time.
Without those hormones in the mix, the growth plates stay open longer than they should, which means the bones keep growing. Sounds harmless, right? Not quite. That extra growth can throw off limb alignment, joint angles, and overall balance in the musculoskeletal system. Think stretched-out limbs, altered posture, and a body that doesn’t quite move the way it was meant to.
This is especially concerning in large and giant breeds, where joint health is already a major concern. Early sterilization has been linked to a higher risk of hip dysplasia, elbow dysplasia, and cranial cruciate ligament (CCL) tears [2] —issues that often show up later in life but have roots in how those bones grew from the very beginning.
Cancer Risks and Hormonal Influence
Hormones do more than manage reproduction—they play a protective role in the body, including influencing how cells grow and respond to stress. Research from the University of California, Davis found that neutering Golden Retrievers before one year of age was associated with a higher incidence of cancers like lymphosarcoma and hemangiosarcoma [3]. Other studies have echoed similar findings across various breeds, suggesting that the absence of sex hormones may leave dogs more vulnerable to certain cancers later in life.
So while science gives us the studies, and experience gives us perspective, your intuition matters too. You know your dog. You live with them, love them, and witness all the little details no research paper ever could. Trust your gut. Ask questions. Make the decision that feels right for your pack, not just the one that fits into a convenient box. You’re not just managing a body—you’re supporting a whole being.
Behavior and Emotional Well-being
Let’s talk puppy brains. Just like kids, dogs go through important developmental stages, and hormones are deeply intertwined with how they process the world. One of the most critical—and misunderstood—windows is what we call the “fear phase.” This typically hits between 8 to 10 weeks and then again around 6 to 14 months, depending on the breed and individual.
During this time, puppies are extra sensitive to their environment. A loud sound, an intimidating dog at the park, or even a vacuum cleaner can leave a lasting impression. Hormones, especially estrogen and testosterone, play a huge role in how these experiences are internalized. Spaying or neutering too early, before the body has a chance to regulate this process naturally, may interfere with how the brain wires resilience, confidence, and social interaction.
Studies suggest that dogs sterilized early are more likely to display fear-based behaviors, anxiety, and reactivity—particularly toward strangers or in new situations. When you leave the hormones in place during these sensitive windows, you’re allowing your dog to develop the emotional intelligence fully and nerve strength they were designed to have.
In short? Early neuter = hormonal static in the middle of emotional boot camp. Waiting gives your dog the biological toolkit to process life in stride.
When To Consider Spay & Neuter:
While the timing isn’t one-size-fits-all, here’s a general guide:
Small to medium breeds (under ~50 lbs): wait until at least 1 year
Large breeds (50–90 lbs): aim for 18 months
Giant breeds (90+ lbs): hold off until around 2 years
Females: Don’t assume they’re done growing after the first heat—wait for two to be safe!
Or longer—depending on your household and lifestyle.
Canine Female Spaying: Additional Considerations
Now, here’s something that often gets misunderstood: just because a female dog has her first heat cycle doesn’t mean her growth plates are fused. That first heat is the biological kickoff of puberty—it tells us estrogen has entered the chat—but it can take several more months for her body to fully close all those growth plates, especially in the long bones.
In small breeds, fusion might follow soon after that first heat. But in large and giant breeds, you’re often looking at a much longer timeline—anywhere from 18 to 24 months. So if you’ve been told to wait until the first heat and then schedule surgery right after, take a breath. You might still be mid-growth. And trust me—I used to be one of those folks who thought getting through that first heat cycle was "good enough." But now? I say wait for two cycles to be sure. It’s a simple shift that can make a big difference in your dog’s long-term structure and soundness.
Canine Male Neutering: My Personal Approach
When it comes to the boys, my personal rule of thumb? "If I can live with you, you can keep your balls."
Yep, I said it. Because it’s not just about hormones—it’s about honoring development, behavior, and the whole picture. When we take time to understand what those hormones are doing behind the scenes, we make decisions that lead to stronger bodies, calmer minds, and fewer vet bills down the road.
Many of you who've followed this blog for a while already know Torch—my soulful, scrappy guy who’s been on a journey with EPI (exocrine pancreatic insufficiency). When I learned of his diagnosis, I made the intentional decision to leave him intact. Why? Because his body was already navigating a major digestive challenge, and I felt that removing his hormonal support would only make that process harder on him—physically, emotionally, and energetically.
Torch’s testicles aren’t about ego or aesthetics—they’re about supporting the hormonal framework his body needs to maintain balance. And honestly? It’s been the right call for him. He’s thriving.
Hormones are helping guide the blueprint of your dog’s body. The longer you can let them do their job, the better chance your pup has at a strong, balanced, joint- happy life. You're not just managing a body—you’re supporting a whole being.
Exploring Alternatives: Hormone-Preserving Options
For pet parents looking to avoid unwanted litters without removing the critical hormones that drive development, there are a couple of standout alternatives.
Vasectomy:
This procedure renders male dogs infertile by severing or blocking the vas deferens—the tubes that carry sperm—while leaving the testicles (and testosterone production) fully intact. That means your dog can no longer father puppies, but hormonally, he’s still very much a male.
He may still exhibit hormone-driven behaviors such as:
Territorial urine marking
Roaming (if given the chance)
Mounting or humping
Male-on-male aggression
And yes—he can still "tie up" with a female in heat
I personally had a client opt for this procedure, and it worked well—until she brought a second male into the household. The two boys started fighting, and unfortunately, the tension escalated. She ultimately chose to go back and have the first dog traditionally neutered, and once his testosterone levels dropped, the aggression stopped. Problem solved—but it was a journey and illustrates that every dog and situation are different.
Ovary-Sparing Spay (OSS):
This procedure removes the uterus but leaves the ovaries intact, allowing a female dog to continue producing estrogen and progesterone—two hormones essential for proper development, bone health, and emotional balance.
I’ve had more and more clients choosing OSS, and overall, they’ve been happy with their decision. Their dogs have matured beautifully, both physically and behaviorally. But be prepared for the price tag—OSS is typically much more expensive than a traditional spay, and fewer vets are trained to perform it.
If you’re exploring either OSS or even a traditional spay, try to find a vet in your area who offers laparoscopic surgery. The incisions are tiny, the procedure is less invasive, and the result is far less scar tissue.
In Conclusion:
One of the best things you can do when weighing your options? Talk to your animal wellness team—the people who know your dog, your lifestyle, and your values. They’ve likely seen firsthand how different sterilization choices play out long term. And don’t underestimate the power of community, sometimes the most valuable guidance comes from someone who’s already walked the path (muddy paw prints and all).
Book a Virtual Pet Wellness consult with Dr. Andi today!
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References:
AKC Canine Health Foundation. "Potential Health Benefits of Delaying Spay/Neuter." akcchf.org
Hart, B. et al. (2020). "Health Implications of Early Spay/Neuter in Dogs." Frontiers in Veterinary Science, 7:388. frontiersin.org
Torres de la Riva, G. et al. (2013). "Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers." UC Davis Veterinary Medicine. akcchf.org