Navigating the Intricacies of Early Desexing and Canine Behaviour

In numerous countries worldwide, routine castration of dogs has become standard practice, primarily aimed at curbing overpopulation that overwhelms shelters and sadly results in the euthanasia of countless dogs. However, alongside addressing population control, neutering dogs has increasingly become a common recommendation by veterinarians, particularly when owners report instances of aggression, especially towards family members.

In the realm of canine behavior, reactivity and aggression stand out as significant concerns for dog owners and trainers alike. Often, when seeking assistance for these issues, owners reveal a common denominator: their dogs were desexed at a young age. This observation sparks curiosity: could there be a link between early desexing and behavioral problems in dogs?

Scientific Research

One of the pioneering studies aimed at investigating the behavioral effects of early spay and neuter procedures was conducted by Dr. Deborah Duffy and James Serpell, titled "Nonsurgical Contraceptive Methods for Pet Population Control." [7] This study utilised the C-Barq method [8] as the basis for assessment. The primary finding of this study was that spayed and neutered dogs exhibited significantly higher levels of aggression compared to intact dogs. This increase in aggression was observed across both male and female dogs, with the degree of aggression varying from a 20% increase to nearly double the level of aggression observed in intact dogs.

Non-reproductive Effects of Spaying and Neutering on Behavior in Dogs Deborah L. Duffy, Ph.D., and James A. Serpell, Ph.D., Center for the Interaction of Animals and Society, School of Veterinary Medicine, University of Pennsylvania.

Duffy and Serpell’s study concluded; “The beneficial effects of gonadectomy [neutering] are underpinned by the need to reduce the number of unwanted companion animals. Thousands of dogs are euthanized in shelters and pounds annually in many developed countries. However, shelters are inundated by dogs that are most commonly surrendered because they display undesirable behaviors. So the current findings present the paradox that castration may reduce the numbers of unwanted dogs but may also increase the likelihood of problem behaviors that reduce the appeal of the castrated dogs and make them more vulnerable to being surrendered."

In 2018, a study was conducted [6] to investigate whether there are discernible behavioral advantages or drawbacks associated with neutering male dogs and to assess whether the age at which the dog underwent neutering played a significant role in influencing behaviour.

In this study, neutered dogs exhibited a higher likelihood of displaying aggression in various scenarios, including when delivery workers approached the home, when strangers passed by, when encountering joggers, cyclists, and rollerbladers, when approached by unfamiliar female dogs, when unfamiliar individuals approached the owner or family members, and even during visits to the home by strangers. Additionally, they showed increased aggression when small animals entered the yard. Notably, the younger the age at which the dog was neutered, the more pronounced these effects became.

Furthermore, neutered dogs displayed a multitude of fear-related behaviors. These encompassed reactions to loud noises, unfamiliar situations, direct approaches by unfamiliar children, barking or growling from unfamiliar dogs, encounters with unfamiliar objects or windblown items on sidewalks, veterinary examinations, and nail clipping. Once again, early neutering appeared to exacerbate these fear-related effects.

Neutered dogs also exhibited a higher incidence of various undesirable behaviors, including eating droppings or feces, rolling in droppings or other odorous substances, food stealing, persistent barking when alarmed or excited, and excessive self-licking. This pattern of results suggests that neutering male dogs can lead to an increase in aggressive, fearful, and over-excitable behaviors, as well as other miscellaneous undesirable behaviors. Furthermore, early neutering seems to magnify these negative effects on behaviour.

A seminal study conducted by Palestrini et al. [1]in 2021 examined the behavioural effects of early neutering and found that it was associated with an increased incidence of noise phobias and undesirable sexual behaviours, such as mounting. This groundbreaking research underscores the need for a nuanced understanding of the effects of desexing on canine behaviour and calls into question the one-size-fits-all approach to neutering.

Expanding on these findings, Starling’s 2019 study [2] provided further insights into the behavioral risks associated with spaying and neutering. The study observed a notable increase in behavioural issues among spayed and neutered dogs, with spayed females exhibiting heightened fearful behaviour and neutered males displaying aggression as a primary concern. These findings challenge the notion that desexing is a panacea for behavioural problems and highlight the importance of considering individual differences in temperament and behaviour when making desexing decisions.

Turning our attention to specific breeds, Zink et al. (2014) [3] investigated the impact of gonadectomy on Vizslas’ behaviour. Their findings revealed that Vizslas subjected to gonadectomy at various ages showed elevated risks of developing fear of storms and behavioral disorders. Notably, those neutered at ≤ 6 months had heightened susceptibility to these issues, with earlier neutering correlating with earlier onset of behavioral disorders. This research underscores the need for a personalised approach to desexing that takes into account breed-specific differences in behaviour and temperament.

In addition, Kim’s 2006 study [4] shed light on the effects of ovariohysterectomy on reactivity in German Shepherd dogs. The study found that bitches aged 5-10 months that were spayed showed more reactivity compared to sexually intact counterparts, indicating a potential link between early desexing and heightened reactivity in this breed. These findings raise important questions about the long-term behavioural effects of desexing and suggest that more research is needed to fully understand its impact on canine behaviour.

Furthermore, Farhoody’s 2018 study [3] added another dimension to the discussion by examining aggression in gonadectomized dogs. While the study found no association between gonadectomy and aggression towards familiar individuals or dogs, it revealed a significant increase in aggressive behavior towards strangers among dogs neutered at 7 to 12 months. These findings highlight the need for careful consideration of the timing and method of desexing, as well as the potential behavioural implications for dogs in different social contexts.

Outdated information

Unfortunately, many veterinarians continue to recommend this outdated procedure as a solution to address behavioural problems related to aggression and over-excitement. This persistence can be attributed to two primary factors. Firstly, veterinary education programs often rely on outdated practices and protocols established in the 1960s, perpetuating the belief in the efficacy of neutering and spaying for behaviour modification. Secondly, there is a financial incentive for veterinarians, as neutering and spaying procedures represent quick and lucrative income streams.

The prevalence of misinformation surrounding neutering and spaying exacerbates the issue. Numerous online sources, including professional organizations like large Humane societies and veterinary groups, disseminate outdated statements regarding the benefits of these procedures.

Common misconceptions include the belief that spaying and neutering make dogs more affectionate, reduce stress and aggression by decreasing sex hormones, and prevent most aggression problems through early neutering. These misleading assertions contribute to the perpetuation of outdated practices and hinder efforts to promote informed decision-making regarding canine reproductive health.

Conclusion

Certainly, while advocating for responsible dog ownership, it's essential to acknowledge that desexing dogs serves a vital purpose in some circumstances. There are individuals who lack the awareness or responsibility necessary to make informed decisions, such as those who impulsively breed their dogs without considering the consequences. Desexing, done at the right age and using the right methods (such as ovary sparing spay’s or tubal ligations) undoubtedly play a role in addressing such issues.

Yet, we must remain open to considering all available evidence (especially paying attention to the most up to date research) rather than adhering solely to a predetermined agenda!

We can promote scientific findings and provide education to empower other dog owners. It's time to shift away from promoting early desexing and instead focus on helping pet parents make informed choices that contribute to the well-being and longevity of our canine companions!

In conclusion, navigating the intricacies of early desexing and canine behaviour requires a holistic approach that considers the latest research findings, individual differences in temperament and behaviour, and the broader implications for responsible dog ownership. By staying informed, engaging in open dialogue, and advocating for personalised desexing decisions, we can promote the well-being and longevity of our furry companions while ensuring a brighter future for canine behaviour science.

If you would like to read more about early spay and neuter and  other impacts click here

Sources

Influence of Gonadectomy on Canine Behaviour: Clara Palestrini, Silvia Michela Mazzola,* Bianca Caione, Debora Groppetti, Alessandro M. Pecile, Michela Minero, and  Simona Cannas 2021[1]

Behavioural risks in female dogs with minimal lifetime exposure to gonadal hormones; Melissa Starling 2019 [2]

Evaluation of the risk and age of onset of cancer and behavioural disorders in gonadectomized Vizslas: MC;Farhoody P;Elser SE;Ruffini LD;Gibbons TA;Rieger RH; [3]

Effects of ovariohysterectomy on reactivity in German Shepherd dogs 2006 Hyeon H Kim [4]

Aggression toward Familiar People, Strangers, and Conspecifics in Gonadectomized and Intact Dogs Parvene Farhoody [5]

McGreevy PD, Wilson B, Starling MJ, Serpell JA (2018) Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of desexing. PLoS ONE 13(5): e0196284.[6]

Nonsurgical Contraceptive Methods for Pet Population Control*, by Dr. Deborah Duffy and James Serpell [7]

About the C-BARQ CANINE BEHAVIOURAL ASSESSMENT & RESEARCH QUESTIONNAIRE [8]