Why you should beware of early neutering

David Tomlinson recently wrote about the physical downsides of early neutering for dogs of either gender, but the behavioural effects are less well known. Many people who experience problems with their dogs, especially male dogs, will be on the receiving end of assurances from all and sundry that any issues will magically melt away the instant the dog is parted from its reproductive organs. Neutering will stop straying, running off, fighting and even (as one of my clients was persuaded) killing wildlife.

In truth, these issues are reliably fixed with a fence, a lead and proper training, but somehow have become mixed up with a dog’s ability to reproduce. Like much received wisdom, not only is it far off the mark but it also won’t go away. We behaviourists pick up the pieces.

During normal development, the mammalian brain receives a cocktail of hormones that rewire it during adolescence to form a well-adjusted adult. We start with a dependent puppy that needs to be with us so follows us everywhere, apparently not needing recall training. Just as we are congratulating ourselves on our easy puppy, adolescence hits like a runaway train. The teenager tests boundaries, human and animal, and is challenging and wilful, swinging wildly between extremes of fretful dependence and anarchy. During this behavioural apocalypse, its brain is undergoing essential development necessary for survival as a social species. The result, if we only allow it, is a competent, co-operative and confident adult dog.

Brain development

However, if these hormones are cut off early, brain development is badly hampered. Pre-pubertal neutering results in a permanent puppy. Lots of people like this. The behavioural downside is a lifetime short attention span and a tendency to tantrum or panic under stress. While unneutered dogs sometimes suffer from separation anxiety or noise phobia, for instance, the prevalence of such behaviours in pre-pubertal neuters is significant. Interaction with other dogs can be tricky too, because what we have is puppy attitude in an adult body and most other dogs don’t like it one bit. Thus we sow the seeds of dog-on-dog aggression, because the early neuter just will not take “no” for an answer.

Adolescence is the time when the majority of dogs are neutered and most dogs given up to rescue kennels are between six months and two years old. If the permanent puppy is a pest, the permanent adolescent is a monster. Adolescence is a time of extremes and a rough ride for both dog and owner but if we hang on in there, those hormones do their work and we gradually realise that the dog has become more sensible, as well as more amenable to training. Owners get embarrassed about adolescent hypersexuality, which is often why people have a dog castrated, but neutered dogs will still hump because such behaviour is not just sexual and can be seen in either gender. Rhythmic repetitive actions release comforting endorphins so the massive loss in confidence from the hormone drop caused by neutering may increase the very behaviour it was supposed to solve.

Stroppy youth

And how many owners are warned beforehand that castrated dogs can still mate and tie, with a real risk of injury, even though there won’t be any puppies? Adolescent challenging of other dogs — “Who are you looking at?” — is naturally grown out of if those hormones are left to create adult brain development and simply need to be managed in the interim. However, if the dog is neutered in the middle of that phase, it is likely to remain a stroppy youth all its life. Far from preventing fighting, neutering may exacerbate it.

In behaviour terms, dogs should not be neutered until adults to allow for proper mental development. Very young dogs are dependent, necessarily selfish and have an extremely short attention span. They go through several developmental fear periods during puppyhood and if they have a sufficiently frightening or difficult experience during this time they may become reactive to that set of circumstances for life. Sensitive breeds or individuals can suffer a catastrophic loss of confidence from neutering, which can exacerbate aggressive behaviour because most aggression (not all) has its roots in fear. Calm, confident dogs with a mature attitude don’t find it necessary to threaten — think of that schoolteacher who only had to walk into the classroom for everyone to fall silent.

Sensible neutering of dogs

Sometimes circumstances make neutering sensible, such as if you have a mixed-gender group of dogs, or if you want to avoid your bitch missing most of a shooting season because she cycles at the wrong time. A few male dogs can be obsessed by sex, and occasionally bitches have troublesome seasons. Keeping dogs that are capable of breeding does involve more care and responsibility and may be impractical in households where not all members can be trusted to close doors and gates. If we wait until our dog is physically and mentally fully grown, then there is little to say against it, unless a dog is exceptionally under-confident. We do have to be aware that as far as other dogs are concerned, even an adult neuter may be a target for bullying if someone else hasn’t trained their dogs as well as we have.

The unneutered dog is the correct design specification, and once development is complete it is a rare adult that continues to be difficult. Even then, behaviour modification is much easier with the entire dog than the pre-pubertal or adolescent neuter. It is far more sensible to retrain the dog first and only neuter once you have a well-behaved adult, if that was your long-term plan. Or you may find that, once trained, there is no need to neuter the dog at all.

When to neuter your dog

Pre-pubertal neuter — under 
six months:

Infant brain — needy and underconfident especially 
if neutered during one of the developmental fear periods.
Difficult to train as low concentration span.
Disliked by dogs for puppy behaviour in adult body.

Adolescent neuter — six to 24 months except giant breeds 
up to four years:

Permanently adolescent behaviour.
Difficult to train as will be
challenging boundaries.
Risk of ongoing 
hypersexual behaviour.
Inappropriate behaviour with other dogs; confrontational and persistent.

Mature neuter — over two years except giant breeds:

Training already done.
Behaviour modification straightforward as has 
co-operative adult brain.
Respected by and respects other dogs.

Additional behavioural issues associated with early neutering:

Separation anxiety.
Noise phobia.
Reactivity.
Underconfidence leading 
to aggression.
Bolting.