Can castration resolve behaviour problems in dogs?

So your adorable puppy has grown up. Puppy playfulness has progressed into hormone fuelled behaviour, some of which you may consider undesirable and, let’s face it, a bit embarrassing. Anyone who has a male dog that humps a visitor’s leg understand the predicament!

 But how do you tackle these behaviour issues? Do you castrate or do you leave intact? Traditionally, castration was seen as the answer to many male dog problem behaviours. But can castration really offer a magic solution?

Behaviours influenced by hormones

The effects of castration on a dog’s behaviour varies from individual to individual and the most important fact to remember is this: the only behaviours that can be changed by castration are those directly influenced by the male sex-hormone, testosterone.

A study by the University of California showed that certain unwanted behaviours may be reduced in dogs following castration:

Urine Marking Behaviour

Most adult male dogs lift their leg while urinating and retain some urine to mark other surfaces as they pass by. Some males may even urine mark indoors and whilst scent marking is fine outside, no one wants to have their sofa or table leg used as a marking post. Dogs with a longer exposure to gonadal hormones are significantly more likely to mark indoors, and castrated dogs may be 50% less likely to mark indoors than intact males.

Roaming behaviour

Roaming is seen as an undesirable sexual behaviour whereby a male will go off in search of a mate. Research shows that a castrated male dog is less likely to roam in 90% of cases because they have less desire to go in search of a mate. However, this is rarely a problem for modern day dog owners, as most pet dogs do not have the ability to roam freely.

Intermale Aggression

The University of California study showed that castrated male dogs are 60% less likely to show aggression to other male dogs and traditionally some vets may argue that aggressive dogs should be castrated.

However, this does not mean that castration can be considered a quick fix for inter-dog aggressive behaviour. A recent study by Farhoody provides a strong behavioural argument against castration and suggests that castrated males are “more aggressive, fearful and excitable and less trainable than intact dogs”.

Other scientific studies support Farhoody’s research. Kaufmann and colleagues in their study into the social behaviour of neutered and intact male dogs said that: “neutered dogs are more likely to become more anxious and insecure”. Furthermore, McGreevy and colleagues found that 26 problematic behaviours were seen to be significantly reduced in dogs that had a longer percentage lifetime exposure to gonadal hormones, of which eight behaviours were related to fear and seven to aggression.

So, by not castrating a dog, or at least by delaying castration until an older age, an owner may have a dog that is potentially less fearful, anxious and aggressive and easier to train.

Humping

Humping is a normal behaviour that is seen in most dogs. Six-week-old pups will mount, clasp and pelvic thrust their littermates possibly as preparation for when they reach sexual maturity. However, this behaviour isn’t just seen in males. Female puppies and dogs will also engage in the humping behaviour. As such, humping cannot be entirely linked to sexual activity.

There appear to be a multitude of situations in which a dog may hump: whilst playing with littermates; in greeting an owner; humping a pillow or greeting a dog in a park. Therefore, it is likely that there are multiple motivations for humping behaviour. In many cases, mounting can be associated with a surge of emotion such as excitement rather than a surge in hormones.

Playful and excited dogs have been observed to be the ones displaying the most mounting behaviour.  Humping may also be a displacement behaviour when a dog is super-aroused non-sexually and cannot decide what activity to engage with. The dog’s build-up of energy and social motivation, coupled with their strong desire to affiliate with another individual, overspills into humping behaviour.

Some dogs hump more than others and a dog may become a recurrent humper simply because humping feels pleasant. This is a form of positive reinforcement, encouraging the dog to repeat the behaviour in the future.

Castration will only impact upon humping behaviour that is sexually driven. However, as described, there are many, non-sexual situations in which a dog may hump which castration alone will not solve.

The importance of behaviour management

So, in short, castration should not be considered an easy fix to problem behaviours, except perhaps for indoor scent marking and roaming behaviours. New scientific research is painting a different picture of the changes in behaviour that can occur because of castration and castration cannot resolve behaviours that are not driven by sex hormones.

My advice to any dog owner considering castration as an option to solve behaviour problems would be to have their dog assessed by their vet to rule out any underlying health problems that might be triggering the unwanted behaviour in the first instance. Castration or temporary chemical castration options should be discussed with their veterinarian. A behaviour consultation could work in parallel with the veterinary advice to develop a behaviour modification plan that would help manage the issues.

Castration remains an important way to control unwanted puppies

Despite the changes in scientific thinking, the most compelling argument supporting castration lies with the need for dog population control. Neutering a dog is seen as the responsible choice for a dog owner in the UK. There are many unwanted dogs with re-homing centres full to bursting with abandoned pets.  Castration may be the sensible choice to remove the risk of further unwanted pregnancies.

Further reading:

Farhoody, P. et al (2018) Aggression Towards Familiar People, Strangers and Conspecifics in Gonadectomized and Intact Dogs. Front. Vet. Sci. [online].

Garde, E; Pérez, G.E; Vanderstichel, R; Dalla Villa, P.F; Serpell, J.A. (2016) Effects of surgical and chemical sterilization on the behavior of free-roaming male dogs in Puerto Natales, Chile. Prev Vet Med 123:106–20.

Kaufmann, C et al (2017) The Social Behaviour of Neutered Male Dogs Compared to Intact Dogs (Canis lupus familiaris): Video analysis, Questionnaires and Case Studies. Veterinary Medicine 2(1). [online].

McGreevy, P. et al (2018) Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of desexing. [online].