Neutering Male Dogs
by David Appleby

The castration of dogs is an emotive issue which veterinary surgeons and behaviourists sometimes recommend to help cure certain behaviour problems. Sometimes the idea is met with resistance, particularly by some male owners, despite all the evidence and arguments raised in favour of the operation.

The subject of castration has to be dealt with rationally as there are definite circumstances where the surgical removal of a dog's testicles can help to improve problem behaviour. Indeed, castration can help prevent the development of some behavioural problems which in addition to the prevention of unwanted litters, is a good reason for the neutering policy adopted by many rescue organisations.

Sometimes owners are reluctant to neuter their dog because they know someone whose dog was castrated but its behaviour did not improve. Sadly there are occasions when this occurs, normally because the operation was not appropriate in the circumstances. For example, an owner may be led to believe that castration may stop the dog being aggressive to other people and dogs, but they will be disappointed if the aggression is motivated by fear, which is not a testosterone (male hormone) related problem. Accurate diagnosis is therefore essential to determine whether castration is appropriate.

As a rule of thumb, castration is most likely to be curative when the problem behaviour is sexually dimorphic. In other words, it is specific to, or more common in, one sex than the other. Males exhibit behaviours which are influenced by testosterone, such as scent marking, roaming away from home to find potential mates, inappropriate sexual behaviour, aggression towards other males, and sometimes rank related aggression within the family which is its substitute pack.

Even when castration is relevant, there is only a percentage chance that it will work. This varies from 90% for some problems, such as roaming to find potential mates, down to 50% for others such as inappropriate scent marking. This is because the male brain is programmed to display male behaviour by testosterone even before birth. If the accurate diagnosis of a problem shows that castration is likely to help, the chances of success are greatly improved if the operation is done in conjunction with behaviour modification therapy, preferably carried out under the guidance of a pet behaviour counsellor such as a member of the Association of Pet Behaviour Counsellors.

One of the emotive arguments against castration is that it is unnatural. Well, yes it is, but we expect our dogs to live in an unnatural world. They are subjected to pressures they would not encounter if they were running wild like their cousin the wolf.

For example, it's natural for packs of wolves to attack any other wolves they encounter on their territory, whereas a dog, which still has many of the same instinctive drives, is expected to accept all the male dogs it meets in the park quite happily. It's natural for males to mark their territory with scent by leaving droplets of urine in prominent places, such as trees, but it's rather distressing if the dog develops the habit of anointing the furniture or the reverend's leg! It's also natural for dogs to compete with other pack members for the right to mate and pass on its genes. However, things can get difficult if this competition is directed at male dogs or male members of the family.

Understandably, dog owners are often concerned about removing their dog's reproductive drive and its potential to mate. However, breeding should not be undertaken lightly - there are enough unwanted dogs as it is. Certainly, mating should never be allowed in the hope that relieving the dog's frustrations will cure his behavioural problems. Once he has bitten that particular apple, his machismo and inclination to perform problem behaviours is likely to increase, not decrease. Perhaps the fact that most dogs are not allowed to mate for fear of creating unwanted puppies is the most convincing argument for the routine neutering of dogs. An unneutered male can lead a frustrated life, especially if he is likely to encounter the smell of bitches on heat. Surely it's better to save him that agony. After all, if he's never read Playdog, he won't know what he's missing!

A booklet entitled ‘The Behavioural Effects of Canine Castration’ by Hazel Palmer fully covers the appropriateness and pros and cons of neutering.