The best time to spay or neuter your hunting dog
Modifying or eliminating the reproductive hormones–especially before the onset of puberty–comes with a long list of consequences that hunters may find desirable, tolerable, or in some cases, dangerous or unacceptable.
Should you wait six months? Two years? Or maybe don’t do it at all? It depends.
(This article appeared in the summer 2025 issue of the American Field Sportsman’s Journal)
As a veterinarian and avid bird hunter, one of the most common questions I receive from sporting dog owners revolves around the decision to spay or neuter their dogs. For many reasons that I’ll lay out in this article, it’s a decision not to be taken lightly nor one that’s easy to navigate.
Unfortunately, you’ll find numerous options, conflicting opinions, and countless anecdotes from fellow hunting dog owners and veterinarians alike. The ambiguity that arises from so many variable sources of advice begins to explain why this topic is so popular with the hunting dog community.
Modifying or eliminating the reproductive hormones–especially before the onset of puberty–comes with a long list of consequences that hunters may find desirable, tolerable, or in some cases, dangerous or unacceptable. Like most things, it all depends on your preference, your past experiences, and your perspective. Hunters should seek a full picture of the risks and benefits of all the options before agreeing to an irreversible surgery with the potential for unintended consequences.
The origins and justifications for the early spay and neuter recommendation
From a 30,000-foot view, much of the world still struggles with a dog overpopulation problem. Globally, dogs are still capable of spreading infectious diseases such as rabies. This scenario has partly contributed to the aggressive (and effective) campaign–put forth by public health officials and spearheaded by veterinarians–to sterilize animals before they could reproduce.
For four or more decades, early spay and neuter (prior to puberty, or at approximately six months of age) has existed as the boilerplate veterinary recommended approach to managing pets of all breeds and sizes. To be fair, this approach works extremely well at preventing unwanted pregnancies and has shown to limit roaming and some forms of aggression in males.
Historically, early spaying and neutering were also thought to reduce the risk of certain health issues, such as potentially life-threatening uterine infections, or pyometra, or mammary tumors in females or testicular cancer in males. Additionally, it is reasonable to assume that spaying or neutering at a young age might prevent a host of sexually transmitted diseases.
On the surface these benefits seem valid. It’s logical to assume that a dog can’t get reproductive disease if it doesn’t have reproductive organs. However, that’s a philosophy akin to throwing the baby out with the bathwater. Emerging evidence has raised questions about whether early spay and neuter are truly and holistically beneficial, particularly for sporting dog breeds.
Until relatively recently, side effects were poorly understood, ignored, or simply tolerated in the name of a higher public health purpose. Most hunters have the discipline and sense of responsibility to prevent unwanted pregnancy in their dogs, so should they still be subjected to the same boilerplate sterilization recommendations? When it comes to the health of our canine athletes, probably not.
Waiting Until Physical Maturity: The Case for Delaying Spay or Neuter
As more research has emerged on the impact of early spaying and neutering on the health of sporting dogs, many veterinarians now recommend waiting until a dog reaches physical maturity—typically between 18 and 24 months of age—before undergoing these procedures. This approach is especially relevant for sporting breeds, which tend to have a longer developmental period due to their size and energy requirements.
First, it’s an established fact that reproductive hormones drive metabolic growth and development. Early spaying and neutering will disrupt the complex signaling pathways involved in the process of reaching full physical maturity.
Hormones, particularly estrogen and testosterone, play a significant role in the maturation of bones, joints, and muscles. These hormones also function in ligament development, especially the cranial cruciate ligament (CCL, or ACL equivalent in dogs). When a dog is spayed or neutered before reaching full maturity, the closure of the growth plates in the bones may be delayed, which can lead to a higher risk of joint issues or cruciate ligament injury.
This risk is particularly important in larger sporting breeds like retrievers, pointers, and spaniels. It’s a phenomenon (and to be honest, a health crisis) linked by a retrospective analysis of data from dogs who suffered from these conditions later in life.
“You’ll find compelling data to suggest tinkering with the body’s reproductive hormonal feedback system affects more parts of the body than just the reproductive system”
Research reinforces what some veterinarians have suggested: There’s a strong and statistically significant correlation between early spay and neuter and musculoskeletal injury in adulthood, potentially from numerous changes directly linked to their early alteration.
Sex hormones also drive metabolism, and their removal greatly impacts how our sporting dogs process energy. I’ve often claimed that obesity is the single largest post-surgical complication related to spaying and neutering, and ironically it rarely gets discussed prior to your veterinary appointment.
Fat dogs live shorter lives, and there are numerous diseases directly linked to obesity that affect multiple systems in the body. The decision to spay and neuter must be made with the promise to monitor and reduce the contents of the food bowl and a renewed commitment to exercise and conditioning.
Behavior changes linked to spay & neuter
Sexual hormones affect brain development and contribute to behavioral maturity. While early spaying and neutering may reduce certain behaviors like aggression and marking, it can also interfere with the natural hormonal regulation of other normal canine behaviors. Delaying the procedure allows a sporting dog to mature physically and emotionally (if you’ll pardon the anthropomorphism here), which can result in better impulse control, less anxiety, and more consistent performance during training.
A retrospective study of vizslas with fear- and anxiety-linked behaviors showed (not surprisingly), a strong correlation between these reported behaviors and spaying or neutering prior to puberty. This research supports the anecdotes of some professional trainers who for many years have claimed early altered hunting dogs show less focus, less drive, less confidence, and more frequent behavioral issues they’re tasked with correcting.
Making sense of cancer risks with spay and neuter
Basing whether or when to spay and neuter on its link to cancer mitigation is murky and complicated. While it’s undeniable that early spaying and neutering reduces the risk of reproductive cancers like testicular, cervical, uterine and ovarian cancers (you can’t get cancers if these tissues are preemptively removed, obviously), recent studies suggest that spayed or neutered sporting breeds may have an increased risk of other cancers, such as osteosarcoma (bone cancer), hemangiosarcoma (a type of blood vessel cancer), and lymphoma (a cancer of white blood cells).
If I had to pick a poison as a veterinarian, I’d gladly tackle the former list of often slow-growing or benign tumor types as opposed to the trifecta of malevolent malignancy presented in the latter.
The full partnership between early spay/neuter and these cancers is still being explored, but you’ll find compelling data to suggest tinkering with the body’s reproductive hormonal feedback system affects more parts of the body than just the reproductive system. Several studies suggest delaying or foregoing spay and neuter may offer some protection against these types of cancers, particularly in larger breeds.
The increased risk of malignant mammary tumors in intact females is well documented in research and in my own clinical experience, and it is indeed rare for early spayed females to develop the types of mammary cancer that is somewhat more common in their un-spayed counterparts. This fact is often used as promotional material for the early spay and neuter camp, but its actual risk to our patients may not be as dire as our profession has for years made it out to be.
Deciding when to spay or neuter a sporting dog is not a one-size-fits-all scenario. While early spay and neuter has been historically recommended for their perceived behavioral and health benefits, emerging research has raised concerns, particularly for sporting breeds.
If you’ve gone down the road of losing a dog to mammary tumors late in life you may be inclined to move towards prevention, but for myself, it’s a risk I’m willing to take if a lifetime of maintaining a normal hormone profile reduces the risk of more aggressive cancers.
Lastly, some veterinarians justify neutering as means to prevent or treat prostatic disease (hyperplasia/hypertrophy or prostatitis). While it’s correct that removing the source of testosterone will help these conditions if they occur, hunting dog owners should keep in mind that neutered males have an increased risk of prostatic cancer overall.
Most prostate enlargement issues can be adequately addressed at the time they arise, and in my opinion it’s borderline overly aggressive to try to prevent this condition with neutering before puberty.
In conclusion
Deciding when to spay or neuter a sporting dog is not a one-size-fits-all scenario. While early spay and neuter has been historically recommended for their perceived behavioral and health benefits, emerging research has raised concerns, particularly for sporting breeds.
Delaying the procedure until physical maturity—usually after 18 to 24 months—appears to have several advantages in terms of joint health, behavior, and even the prevention of some cancers.
However, each dog and owner is unique, and the decision should be made based on the specific needs of the breed, the individual dog’s health, and the owner’s goals and comfort level with certain risks.
Ultimately, you should consult with a veterinarian who understands the nuances of sporting breeds and incorporates the latest research into their recommendations. This thoughtful approach ensures that you have the full picture of the risks and benefits, and you’re fully prepared to develop a health plan custom tailored to you and your hunting dog.
