HINDES HOUNDS – CANINE BEHAVIOUR AND TRAINING. The Balanced Guide to Neutering Dogs Part 1:
- Pamela Hindes
- May 28
- 6 min read
(BLOG One of a Series of Three IMPORTANT Blogs on Neutering)
Understanding both the Potential Health Benefits and Costs.
Introduction
Neutering your dog is a significant decision, and as a responsible pet owner, you’re likely seeking guidance that goes beyond a simple ‘yes’ or ‘no.’ At Hindes Hounds, we believe in providing balanced, research-backed insights to help you make the best choice for your canine companion.
This article is one of three in a short series created to help dog owners make informed, balanced decisions about whether and when to neuter their dogs. Each guide explores the issue from a different angle, using the latest scientific research and practical experience to offer nuanced, accessible advice. This Article is mainly looking at health implications. The second looks at behavioural implications and the last (third) at other external influences that may sometimes put pressure on us to make certain decisions in regard to neutering.
Deciding whether to neuter your dog isn't always straightforward. Neutering means removing your dog’s ability to reproduce — this includes spaying for females and castration for males. It can affect your dog’s health, behaviour, and how they experience the world. These guides break down the benefits and risks of neutering in clear, easy-to-understand terms so you can make the best choice for your individual dog.
POPULATION CONTROL
I could not start a blog on health issues around neutering without starting with what is probably one of the most common reasons cited for thinking about neutering, which is to reduce the number of unwanted litters and, in turn, control the dog population.
I appreciate that my view may not be popular in some circles but nevertheless it remains my view.
The population control rationale has historically been very valid and indeed remains so in some areas, especially in areas with large numbers of free-roaming or stray dogs.
However, in the modern UK context, the population control argument holds less weight for many pet owners. Most dogs today live in controlled environments — they are kept indoors, exercised on lead or in secure fields, and generally not free to roam unsupervised. Accidental matings are, as a result, much less common than they once were.
As McGreevy et al. (2018) 1 point out, the relevance of neutering for population control needs to be assessed in light of the individual dog’s lifestyle. For a well-managed, responsibly owned dog who is unlikely to encounter intact mates, the population control benefit may not outweigh other health or behavioural considerations.
That said, for dogs living in multi-dog households, in rescue settings, or where unplanned mating is a genuine risk, neutering remains an important tool. As always, it comes down to context.
Understanding the Science Behind Neutering
There is a plethora of science out there dealing with the subject of neutering and the potential health benefits and costs. I have simply picked the most relevant and/or up to date studies to illustrate the main health concerns that we should be considering. If you have particular concerns re your specific breed and/or age-related issues re neutering for example more specific individual advice from a trusted Vet up to date with current health research should be sought.
HEALTH
Health Benefits and Potential Risks
Cancer Risk: Sometimes Lower, Sometimes Higher
Spaying a female dog has long been promoted as a way to reduce the risk of mammary (breast) cancer. However, recent systematic reviews suggest that the evidence for this benefit is more limited and less conclusive than previously thought. 2 What is clear, though, is that spaying does prevent pyometra — a serious and potentially life-threatening infection of the womb that tends to affect older unspayed females. However, it’s worth noting that in rare cases, if any uterine or ovarian tissue is left behind after surgery (as may occur in an incomplete spay), a condition called stump pyometra can still occur. This usually requires additional surgery to treat.
In male dogs, neutering prevents testicular cancer completely (because the testicles are removed). It also lowers the risk of benign prostatic hyperplasia (BPH) — a non-cancerous enlargement of the prostate that can lead to urinary problems or discomfort, especially in older males. A 2021 study 3 confirmed that removing testosterone through neutering causes the prostate to shrink back down over time.
However, Neutering Is Not Without Risks
While neutering can help prevent some reproductive-related conditions, a growing number of studies have found increased risks for several other types of cancer. Research has highlighted elevated rates of bone cancer (osteosarcoma), particularly in large breeds like Rottweilers and Golden Retrievers, as well as a potential increase in hemangiosarcoma, a cancer of the blood vessels that often affects the spleen and heart. One large-scale study also found that neutered dogs were more likely to develop mast cell tumours, lymphoma, and transitional cell carcinoma, depending on the breed. A comprehensive breed-specific review 4 documented significantly higher cancer rates in neutered dogs of several breeds, emphasising that the effects of neutering are not uniform across all dogs. Additionally, a study on prostatic carcinoma showed it is more common in neutered males 5, particularly in Rottweilers. In this study, neutered male Rottweilers were found to be at significantly higher risk of developing prostate cancer compared to their intact counterparts, suggesting a potential protective role of testosterone against this specific cancer type. Although this form of cancer is relatively rare overall, the incidence in neutered Rottweilers was notably higher than the estimated population average of 1%, underscoring the need to consider breed predispositions when evaluating cancer risk. These findings suggest that health outcomes following neutering are complex and highly individual, underscoring the need for breed-specific, age-informed decisions. For instance, Among the breeds studied, Golden Retrievers showed some of the most pronounced negative health effects from early neutering, with significantly increased risks of joint disorders (such as cranial cruciate ligament tears) as well as cancers including lymphoma and hemangiosarcoma. Labrador Retrievers also show increased risks of mast cell tumours and orthopaedic conditions when neutered early, but the effects appear less pronounced compared to Goldens. These differences highlight the importance of looking beyond generalisations and considering how neutering may affect your specific breed. The Hart et al. (2020) study (see ref 4. ) examined 35 dog breeds and found that early neutering had dramatically different effects depending on breed. For example:
Golden Retrievers neutered before 6 months had a 4–5x increase in joint disorders and 3–4x higher risk of cancers like lymphoma and hemangiosarcoma.
Labrador Retrievers also showed increased risk, especially for mast cell tumours and joint problems, though to a lesser extent.
German Shepherds neutered before 1 year had significantly more joint issues but did not show a cancer increase.
Boston Terriers neutered early had a notable increase in cancer incidence.
This data reinforces the importance of breed-specific neutering decisions, ideally made in consultation with a vet familiar with the latest research.
TIMING MATTERS
Research suggests that the age at which a dog is neutered can impact health and behavioural outcomes. For example, neutering before a dog reaches physical and behavioural maturity may increase the risk of joint disorders in large breeds, and in some cases, may contribute to increased anxiety or reactivity. On the other hand, waiting too long in high-risk environments (e.g., where accidental mating could occur) carries its own concerns.
Breed, sex, size, lifestyle, and purpose (pet, working, sporting) all influence what timing is optimal. For large and giant breeds, many vets now recommend delaying neutering until the dog is at least 12–18 months old to allow for full development. Smaller breeds may not face the same growth-related risks and might benefit from earlier neutering in some cases.
As with all elements of care, timing decisions should be made in consultation with a well-informed veterinary professional — and, ideally, a behaviourist if behaviour is a concern.
Behaviour Note: For readers interested in how neutering might influence behaviour — such as roaming, marking, aggression, or anxiety — please see our companion blog post, the second in this series of three blogs specifically focused on the behavioural effects of neutering.
References
McGreevy, P.D., Wilson, B., & Starling, M.J. (2018). Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of desexing. PLOS ONE, 13(4), e0196284. https://doi.org/10.1371/journal.pone.0196284
Beauvais, W., Cardwell, J.M., & Brodbelt, D.C. (2012). The effect of neutering on the risk of mammary tumours in dogs – a systematic review. Journal of Small Animal Practice, 53(6), 314–322. https://doi.org/10.1111/j.1748-5827.2011.01220.x
Cazzuli, G., Damián, J.P., Molina, E., & Pessina, P. (2021). Post-castration prostatic involution: A morphometric and endocrine study of healthy canines and those with benign prostatic hyperplasia. Reproduction in Domestic Animals, 56(6), 982–990. https://doi.org/10.1111/rda.14036
Hart, B.L., Hart, L.A., Thigpen, A.P., & Willits, N.H. (2020). Assisting decision-making on age of neutering for 35 breeds of dogs: associated joint disorders, cancers, and urinary incontinence. Frontiers in Veterinary Science, 7, 388. https://doi.org/10.3389/fvets.2020.00388
Cooley, D.M., Beranek, B.C., Schlittler, D.L., Glickman, N.W., Glickman, L.T., & Waters, D.J. (2002). Endogenous gonadal hormone exposure and bone sarcoma risk. Cancer Epidemiology, Biomarkers & Prevention, 11(11), 1434–1440. https://pubmed.ncbi.nlm.nih.gov/12433723/
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