Understanding Neutering in Tibetan Mastiffs: A Comprehensive Guide

Foreword

As both a lawyer and a certified canine behaviourist specialising in Tibetan Mastiffs, I approach topics like neutering with deep respect for the complexity involved. This blog is not intended to prescribe a single “correct” path, but to help equip owners with evidence-based insights and help you understand your dog better so you can make the best decision for them.

I’ve lived with both intact and spayed Tibetan Mastiffs. I have friends who have also done so, some with considerable first-hand experience of the difference that neuter status can make. I’ve seen firsthand how hormonal changes can influence behaviour, confidence, and physical development. My goal is to help owners make informed, compassionate decisions. This may mean deciding to neuter or not to neuter, delaying neutering, exploring alternatives, or simply understanding the science behind their dog’s behaviour and how neutering may or may not change such behaviour.

This supplemental blog (to my main blogs on neutering) is part of a broader educational series aimed at empowering Tibetan Mastiff owners and breeders with honest, breed-specific guidance. If you have questions or thoughts, I’d love to hear from you. I recommend reading it alongside and as a supplement to my general blogs (there are three in a three-part series) on neutering and spaying.

For owners of Tibetan Mastiffs, decisions around neutering or spaying are rarely straightforward. These dogs mature slowly, both physically and neurologically. Their behavioural development is deeply intertwined with hormonal regulation. While conventional advice often promotes early neutering as a behavioural solution, emerging research suggests that timing and breed-specific context matter far more than previously acknowledged.

Behavioural Impacts of Early Neutering in Tibetan Mastiffs

Two large-scale studies published in PLOS One—one on males by McGreevy et al. (2018) and one on females by Starling et al. (2019)—found that dogs with minimal lifetime exposure to gonadal hormones showed increased risks of fear, anxiety, and aggression. These findings challenge the assumption that neutering universally improves behaviour and highlight the need for breed-specific caution.

• McGreevy et al. (2018): Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0196284

• Starling et al. (2019): Behavioural risks in female dogs with minimal lifetime exposure to gonadal hormones https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0223709

  
  

In Tibetan Mastiffs, whose social and territorial instincts are finely tuned, premature hormone withdrawal may disrupt natural behavioural calibration. Owners often report increased reactivity or reduced confidence post-neutering, especially when performed before full maturity. It should not be forgotten that full maturity for a Tibetan Mastiff is much later than for most other breeds of dogs, typically 3-4 years for females and 4-5 years for males.

Cognitive and Social Functioning

Scandurra et al. (2019) found that ovariectomy impaired socio-cognitive functions in female dogs. This suggests that ovarian hormones play a role in processing social cues and environmental stimuli. For guardian breeds like Tibetan Mastiffs, this results in them being less adaptable or responsive in social situations.

• Scandurra et al. (2019): Ovariectomy impairs socio-cognitive functions in dogs https://www.mdpi.com/2076-2615/9/2/58

  
  

Physical Development

In working and large-breed dogs, early neutering has been linked to delayed closure of growth plates, joint instability, and changes in coat texture. Zink (2014) cautioned against early spay-neuter in canine athletes. Hormonal timing affects musculoskeletal integrity and temperature regulation, both critical for Tibetan Mastiffs living in variable climates.

• Zink et al. (2014): Early spay-neuter in the canine athlete https://www.aubreyenglishspringers.com/uploads/6/9/6/1/69617207/early_spay-neuter_in_the_canine_athlete_by_chris_zink_dvm_phd.pdf

  
  

Coat Condition

Can Spaying or Neutering Affect a Dog’s Coat?

Yes — especially in long-haired breeds like the Tibetan Mastiff. A veterinary study looked at how spaying affects coat condition in female dogs. Here’s what they discovered:

About 1 in 5 dogs had noticeable coat changes after being spayed. These changes included woollier, thicker, or duller coats. The changes are linked to hormone shifts, especially the loss of estrogen or testosterone. Some dogs improved when given hormone treatments, showing that hormones play a role in coat health.

What This Means for Tibetan Mastiffs

Tibetan Mastiff owners often report more shedding and a coat that’s harder to manage. This study supports what many TM owners already observe: hormones matter, and neutering can affect the coat.

Hubler, M., Reichler, I. et al. (2008). Spaying-induced coat changes: the role of gonadotropins, GnRH and GnRH treatment on the hair cycle of female dogs. Veterinary Dermatology, 19(2), 77–87. https://pubmed.ncbi.nlm.nih.gov/40359978

Skeletal and Developmental Maturity in Tibetan Mastiffs

Maturity Timeline Overview

Type of Maturity	Typical Timeline	Notes
Growth Plate Closure	18–24 months	Marks the end of longitudinal bone growth; often used as a benchmark for minimum sterilisation age
Structural Expansion (head, chest, ribcage)	Up to 4–5 years in males	Includes secondary ossification, muscle mass, and breed-specific features like skull breadth
Hormonal and Behavioural Maturity	3–5 years	Affects coat, temperament, and social signalling; especially relevant in intact males

Although growth plate closure typically occurs around 18–24 months, Tibetan Mastiff males continue to expand in head, ribcage, and overall mass well into their fourth or fifth year. This extended maturation period challenges one-size-fits-all sterilisation guidelines and supports a breed-specific approach.

While there are no studies directly relating to Tibetan Mastiffs, a very interesting and useful peer-reviewed study provides evidence for delaying sterilisation in large, slow-maturing breeds:

Hart, B.L., et al. (2020). Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs. https://www.frontiersin.org/articles/10.3389/fvets.2020.00388/full Found increased joint disorders and cancer risks in large breeds neutered before 12 months.

What Neutering Interrupts – Beyond Mating

In intact male Tibetan Mastiffs, seasonal behavioural changes—such as food refusal, restlessness, and vocalisation—often occur in autumn, even without females nearby. These shifts are driven by internal hormonal rhythms, not just pheromonal exposure. Neutering may suppress these natural cycles, altering drive, appetite, and behavioural expression. For primitive breeds like Tibetan Mastiffs, this isn’t just about preventing mating—it’s about respecting their seasonal biology. We really do not yet fully know what ‘knock-on’ effects interfering with such things may have over time on the health and mental well-being of these dogs.

Other Options

If you’re looking for ways to support your dog’s behaviour without surgery, some new research on natural supplements shows promise. Arroub & Pereira (2025) studied Ashwagandha in dogs (it was in fact geriatric dogs who are more likely to be prone to stress) and found it helped lower stress and anxiety due to its beneficial effect on the gut biome. This is another rapidly emerging area of research, but a matter for another blog. It’s not a replacement for good training or responsible breeding, but it and other supplements that are beneficial for the gut might help intact dogs handle stress better.

• Arroub & Pereira (2025): Ashwagandha and stress modulation in dogs https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1491989/full

  
  

Final Thoughts

Neutering is not a one-size-fits-all solution—especially for breeds like Tibetan Mastiffs. Owners deserve access to balanced, evidence-based guidance that respects both the science and the individuality of their dogs. Whether you choose to neuter, delay, or explore alternatives, the goal is the same: to support your dog’s wellbeing with compassion and clarity.