Owning a dog is a pleasure but, increasingly, owners are made to accept responsibility for their. dogs' behaviour- both legally and in terms of social awareness.  Consequently, many of them seek ways to prevent their dog causing a nuisance and wish to know how to cure or, better still, avoid the behavioural problems they do or could encounter.

To this end neutering is often considered.  However, as there is “no going back!” many owners seek information about the possible effects before making a decision.  This owner's guide has been designed to give a basic understanding of neutering, the behavioural problems it may help to prevent/cure and those it is unlikely to affect.  It also outlines possible side effects so that an informed decision can be made in consultation with the veterinary surgeon.

HORMONES - what makes a dog male?
THE UNBORN PUPPY: the main hormone involved in determining whether a puppy displays male rather than female behaviour is testosterone.  Late in development the male foetus generates a surge of testosterone which has the apparent effect of masculinising areas of the brain (Hart & Ladewig 1979).  So, in addition to the obvious physical differences, puppies are orientated to masculinity by alterations in the brain before birth.

THE MALE ADOLESCENT: behaviour variations can be identified between the sexes even in very young puppies.  In the male puppy testosterone is increasingly produced by the testes so that by 6-7 months (i.e. puberty) the levels of this hormone are high enough to activate secondary sex characteristics such as leg lifting, mounting and aggression which will enable it to compete, mate and reproduce in adulthood.

WHAT DOES NEUTERING MEAN?
The term neutering or CASTRATION in reference to male dogs is the surgical removal of the testes during a minor operation, performed under general anaesthetic.  Usually a dog is admitted in the morning and collected later the same day.  He may have several stitches which will be removed after about 10 days.

WHAT ARE THE MAIN REASONS FOR NEUTERING DOGS?

1. OWNER RESPONSIBILITY RELATING TO POPULATION CONTROL.
Thousands of unwanted dogs and puppies are destroyed every year, many from litters born as a result of "accidental matings". To prevent further unwanted puppies being born most Dogs' Homes now specify that dogs must be castrated and bitches must be spayed, either before rehoming or at a later stage, as part of the new owner's agreement to adoption.

2. MEDICAL/HEALTH.
Veterinary surgeons may recommend castration for several medical conditions including testicular tumours, enlargement of the prostate gland, certain types of anal tumours and cryptorchidism ( retained testicles:- if the testes have not descended into the scrotum by about 10 months of age they are unlikely to do so and are prone to tumours in later years

3. UNWANTED DOGS:
If you visit a home for unwanted dogs you are likely to see more dogs than bitches.  Many will be between 1-3 years of age.  One of the reasons owners frequently give for rehoming relates to the behavioural problems mentioned below.

4.  BEHAVIOURAL PROBLEMS.
As their puppies change to adolescents and then to adults, owners are sometimes surprised by changes in behaviour particularly if they are objectionable.  Changes may become apparent from the age of 6-7 months to full social maturity between 1-3 years dependent upon the breed of dog.

Of course not all male dogs become difficult as they mature but we should be aware of the potential for change.

Sometimes owners feel that their dogs suddenly act in an unacceptable manner but problems normally develop gradually.  The first sign of change is often a lack of obedience.  The puppy that used to stay close to its owner on walks and came when called may turn into an adolescent who is independent and more interested in playing with other dogs and bitches than staying with his owner.  He may also become increasingly involved in "disagreements" with other dogs, even those he played with as a puppy.

At home, young male dogs can become increasingly difficult to live with.  Examples of the most frequently mentioned problems are:

1. An increasing possessiveness over toys, stolen articles or food and growling at the owners in an attempt to defend them.
2. A general reduction in response to the owners commands and an increasing tendency to boisterous behaviour.
3. An increase in aggressive territorial behaviour towards visitors.
4. A puppy originally introduced as a companion for an older male dog can become increasingly aggressive towards it.
5. Previously house trained puppies may start to lift their legs and urinate on the furniture.

SEXUAL DIMORPHISM: what is it?
Many behaviour patterns are common to both dogs and bitches, such as tail wagging, grooming, play and greeting.  SEXUALLY DIMORPHIC BEHAVIOURS are unique to, or typical of, each sex, e.g. bitches display a variety of characteristics that relate to their oestrus cycle and maternal care which are not seen in male dogs.  There are behaviours which occur more commonly in male dogs such as scent marking, mate seeking, mounting and aggression.

Before looking at problems where castration may or may not be helpful, we should first consider normal canine behaviour.

NORMAL BEHAVIOUR.
So called "problem" or "nuisance" behaviours are often aspects of normal canine behaviour.  However the environmental and lifestyle restraints under which we expect our dogs to live are often so unnatural, it is not surprising that canine drives and instincts can occur at unacceptable times and in inappropriate places with possible antisocial or even dangerous consequences.

In the wild however these behaviours would have positive benefits for the domestic dog's ancestor, the wolf.  Some examples are discussed below.

URINE MARKING:
In the wild marking territory with urine is a valuable method of keeping out intruders and avoiding the need for aggressive encounters with other packs.  Domestic dogs urinate to inform others which areas they regard as their territory.  Urine is normally deposited on prominent, vertical places in the environment such as lamp posts and trees.  The superior canine sense of smell allows individuals investigating these marks to gain information about the status of the previous dog.  The height of the urine mark may also denote status.

TERRITORIAL AGGRESSION BETWEEN MALES:
In support of the competition to reproduce and pass on their genes, males of most species are aggressive to strange males encountered in their territory.  Domestic dogs have to meet other dogs on what they regard as their territory i.e. streets and parks they have scent marked, yet we expect them not to show aggression.

AGGRESSION BETWEEN COHABITING MALE DOGS:
In packs of wild canids, individuals either establish a hierarchy or one of them has to leave the group.  In our homes the lack of space forces dogs into situations that would not occur naturally.  Additionally the varying size and temperament characteristics of each breed and/or the owner's tendency to unwittingly upset the established pecking order can exacerbate the situation.

MOUNTING:
This is normal sexual behaviour and a necessary function in the mating process.

POSSESSIVE AGGRESSION:
In the wild this may take the form of guarding food.  In captive wolves it has been observed that alpha males tend to guard their potential mate at the high point of her oestrus cycle and will subsequently guard her offspring.  Dominant domestic dogs sometimes adopt their mistress as the surrogate "alpha bitch" (no comments please, Ed!) and attempt to prevent her "partner" from "interacting" with her.  They may also guard new born babies as if they were their own, become possessive over food, toys and stolen items.

ROAMING:
Dogs may travel many miles to find a mate.  The desire to roam is increased if a bitch in oestrus is detected, the scent of which can be carried over long distances.

BREEDING SEASONS:
Female wolves have only one breeding season per year, during January or February.  At this time the normally stable pack structure may become unsettled.  As a result of domestication and man's selective breeding female dogs come into oestrus twice a year and in any month. Consequently males are frequently subjected to the smell of bitches in oestrus which is an unnatural state of affairs.  This can make them territorial, agitated, prone to aggression, off their food, difficult to control and of course sexually frustrated.

CASTRATION - will it work?
Research has shown that where castration is carried out response rates vary.  Of the individuals that are likely to respond, some will do so within two weeks.  The remainder will respond within six months (Hopkins 1976).

The following are examples of situations which prompt owners to consider having their dog castrated.

MY DOG IS AGGRESSIVE TOWARDS THE FAMILY.  WILL CASTRATING HIM CURE THE PROBLEM?
There are many reasons why aggression towards family members develops and determining the motivation can be difficult.  It is very important to discuss the problem with your veterinary surgeon who may (if the aggression is identified as dominance aggression), advise on a programme of treatment or refer you to a behaviour counsellor so that the style of owner/ dog interaction, which may have led the dog to assume dominance, can be altered to demote the dog without confrontation. (Confrontation can unwittingly cause more rather than less aggression.)

Surveys have shown that dominance or rank aggression is seen more frequently in entire males than castrated animals, so your veterinary surgeon or behaviour counsellor may, in addition to the behaviour modification programme, recommend castration and/or a course of hormone treatment.

MY DOG IS AGGRESSIVE TOWARDS VISITORS.  WILL CASTRATION HELP TO PREVENT THIS?
As with aggression towards family members the reasons for the behaviour must be established by an experienced counsellor.  The dog may feel he has the RIGHT to guard the home and may behave in a generally dominant way, so castration may help (see above).  Contrary to the fears of some owners, castration will not affect the dog's ability to be an effective watchdog.  He will still bark if disturbed!

Conversely, a dog may act aggressively due to fear.  At the threshold the apparent success of the behaviour causes it to become overt, i.e. most people who approach the house go away again.  The postman is a good example of this.  This in time may encourage overt displays of aggressive behaviour to visitors allowed into the home.  In this case castration will not help.

MY DOG IS NERVOUS AND AGGRESSIVE TOWARDS STRANGERS IN THE STREET.  WILL CASTRATION STOP THIS BEHAVIOUR?
Castration is definitely not recommended as a cure for nervous or fear aggression.  This condition is often caused by lack of socialisation with people during the dog's early life, or due to subsequent bad experiences. It is not related to the dog's hormonal state. The implementation of behaviour modification techniques is the only viable course of action.

MY TWO MALE DOGS FIGHT.  SHOULD I HAVE BOTH CASTRATED?
Fights between dogs within the home are frequently due to them trying to establish a hierarchy.  It may be that a younger dog is trying to assert himself over his older companion, or that both dogs are so similar in age, size and temperament that it is difficult for them to establish a pecking order.  Fights are sometimes noisy with little physical damage but can become serious.  Fights are most often caused by the owners, who upset the status quo.

To cure the problem it is necessary for the owner to acknowledge and reinforce the status of the dominant dog.  Your veterinary surgeon or behaviour counsellor will advise how to achieve this.  In most cases owners also have to learn how to establish themselves as dominant over both dogs which helps to inhibit their inclination to fight with each other.

Castration can be helpful in these cases but it is important to identify which dog is most likely to assume the more subordinate role and castrate that dog first to increase the status gap.  If the problem is not resolved in a reasonable period of time and the other dog continues to be aggressive it can be castrated as a very last attempt.

MY DOG IS FINE WITH OTHER DOGS WHEN HE IS OFF THE LEAD BUT AGGRESSIVE TOWARDS THEM WHEN HE IS ON THE LEAD.  SHOULD HE BE CASTRATED?
In the early development of fear aggression the dog is content that it can move away if threatened when off the lead.  When it is on the lead this is not an option so the dog learns to use aggression to make the potential threat go away and because he is usually successful the level of aggression can increase and may eventually become so overt that it is displayed off the lead as well.

Castration is unlikely to alter this behaviour as it is related to fear rather than hormone status.  Castration may even exacerbate the problem in individuals that subsequently attract other dogs and provoke further fearful behaviour (see "Are there disadvantages to castration).

MY DOG IS AGGRESSIVE TOWARDS OTHER DOGS WHEN HE IS OFF THE LEAD.  SHOULD HE BE CASTRATED?
If he is aggressive to both sexes it may be that he was not socialised properly as a puppy and his behaviour is due to a lack of canine social skills.  A lack of socialisation or the memory of being attacked may result in fear aggression which may be non-discriminatory or restricted to individuals resembling the breed of the original attacker.  In these cases castration is unlikely to help. If the aggressive behaviour developed after the dog reached maturity and is orientated specifically towards other males, castration is likely to help.  It is believed to work in three ways:

1. Castration may improve the aggression threshold i.e. a greater level of provocation is required to trigger aggression.
2. It reduces the desire to dominate.
3. The dog smells less masculine and challenging so other dogs are less likely to act aggressively.

MY DOG FREQUENTLY LIFTS HIS LEG AND URINATES IN THE HOME. WILL CASTRATION REDUCE THE PROBLEM?
This problem can develop in male dogs once they reach puberty. It usually occurs in regular locations, normally vertical ones such as curtains, the legs of chairs etc.  Urine marking may often be triggered by the presence of another dog, an in season bitch in the vicinity, the introduction of new furniture, or even visitors legs or shopping bags which have the smell of other dogs on them.  Scent marking may also occur in new locations such as another person's home.

In a survey relating specifically to urine marking in the home, castration was found to be effective in 81 % of cases (Palmer).

Scent marking in the home is seen more frequently in small dogs than large ones and is often related to dominance.  A behaviour modification program to lower the dog's status may be required in conjunction with castration.

MY DOG CONSTANTLY STOPS TO URINATE ON TREES, POSTS AND WALLS.  HIS BLADDER MUST BE EMPTY BUT HE STILL MANAGES TO SQUEEZE A DROP OUT.
This behaviour is caused by a dog's desire to leave his scent in the areas that he regards as his territory.  Primarily you should increase control over the dog to prevent this behaviour - after all it is you as "top dog" who should be scent marking the area. (Don't do it though, you'll get arrested!  Ed. ). Significantly, some owners observe that their castrated male dogs urinate less frequently, so castration can be recommended for this problem, but not in isolation.  Improved owner status and control has a strong bearing on the situation.

MY DOG IS DESTRUCTIVE WHEN I LEAVE HIM.  WILL CASTRATION CALM HIM DOWN?
Destructiveness is normally due to anxiety induced by owner absence (separation anxiety).  Castration will not have any effect on this behaviour.  A few dominant dogs do become destructive as a result of frustration and annoyance at being left by " their pack".  In conjunction with a behaviour modification programme, castration may help reduce the dog's desire to dominate, but these cases are rare.  A careful study of your relationship with your dog and the type of damage it does should reveal the causes of the problem.

MY DOG CONSTANTLY PESTERS AND SOMETIME MOUNTS BITCHES.  WILL CASTRATION STOP THIS?
Owners can be forced to keep their dog permanently on the lead to prevent this and the resultant decrease in exercise ca create other problems.  Castration can be very effective in these cases and frequently has a quick result.  Many owner have commented that after castration their dog can be allowed off the lead and that they stay much closer, although dogs still need to be trained.  Castration will not turn them into obedient dogs, it will only reduce the inclination to chase prospective mates.

MY DOG CONSTANTLY ESCAPES AND STAYS AWAY FROM HOME.  WILL CASTRATION STOP THIS?
If your dog gravitates towards homes where there is a bitch rather than going on hunting or scavenging expeditions, the answer is yes.  The reasons for this behaviour are similar t those above.  Castration is successful in about 90% of case (Hopkins). Dogs will travel long distances in search of a bitch and are a risk of causing road accidents.  In addition, many dogs become lost every year and add to the numbers in dog's home throughout the country, so in this instance castration is responsible course of action.

MY DOG MOUNTS PEOPLE'S LEGS.  WILL CASTRATION STOP THIS?
Mounting behaviour is normal in puppies and is frequently triggered by hormone changes during puberty.  It is often see when the dog becomes excited or after feeding. Young children are often mounted because their response is rewarding.  They may laugh or scream and are unable to push the dog away.  If the behaviour continues in adulthood then castration is advisable.  It is successful in 90% of cases (Palmer). In some dogs mounting can be an extension of dominant behaviour, in much the same way as rape in our own species is related to power and not sex.  If there are other dominance problems with the dog, such as aggression, behaviour therapy will be required.

MY DOG MOUNTS THE CUSHIONS WHEN HE IS EXCITED.  WILL CASTRATION STOP THIS?
This behaviour (which is pleasurable for the dog) is frequently associated with items such as cushions, a blanket or even a large fluffy toy!  If mounting continues after puppyhood and causes concern then castration is advisable.  In one survey (Palmer 1989) great improvement was seen in 87% of dogs. Dogs will sometimes display this behaviour purely as an attention seeking device so it is important to ignore it and if necessary remove the item or items for a while.

SHOULD I USE MY PROBLEM DOG AT STUD TO RELIEVE HIS FRUSTRATIONS?
It is a fallacy that allowing a dog to mate will stop problem behaviours.  In many instances things get worse as the dog's sense of status and his interest in bitches is increased. To avoid unwanted puppies only those dogs which carry very desirable traits should be used at stud.  These may be show dogs that are proven to have good temperaments or those known to produce good working lines.

IS IT CRUEL TO TAKE AWAY A DOG'S DESIRE FOR SEX?
In the vast majority of cases pet dogs are not allowed to mate but their instinctive drive can cause problems and frustration.  Once the drive to reproduce is removed by castration, dogs seem more content.  They have no abstract concept of what they are missing.

I HAVE A MALE DOG BUT HAVE NOW OBTAINED A BITCH WHICH I MAY WANT TO BREED FROM.  SHOULD 1 HAVE THE MALE CASTRATED?
It is increasingly common to own more than one dog to provide companionship for them while the owners are at work.  Owners who have a male dog as well as an entire bitch will encounter problems when she comes into season.  Male dogs can suffer greatly at this time.  They may go off their food and have been known to break through doors, jump through windows or even scale incredible heights to reach "their" bitch!

If you wish to keep a bitch entire because of the desire to breed from her then having the male castrated will at least avoid the mental anguish he will go through every season.

It is important to remember that, if the dog is castrated close to the bitch's season, they should be kept separate as fertile sperm may be present for several weeks following surgery.

MY NEIGHBOURS HAVE A BITCH AND MY 7 YEAR OLD DOG HOWLS AND WILL NOT EAT WHEN SHE COMES INTO SEASON.  IS HE TOO OLD TO BE CASTRATED?
No, castration has been found to be effective for this type of problem even in older dogs.

ISN'T IT UNNATURAL TO CASTRATE DOGS?
Yes, but it is also UNNATURAL to bring up male dogs in an artificial environment and expect them not to behave like male dogs!  It is surely kinder to ensure that they do not have urges they are not allowed to express for fear of producing yet more unwanted puppies?

MY VETERINARY SURGEON SUGGESTED THAT HORMONE TREATMENT MAY CHANGE MY DOG'S BEHAVIOUR.  WHY?
It is possible to alter a dog's behaviour by the use of synthetic hormones and hormone inhibitors.  These treatments are normally given in the form of injections or tablets.  Hormone treatment can give owners time to modify the way they interact with their dog to change its behaviour without the need for castration. -

CAN HORMONE TREATMENTS BE A GUIDE TO THE EFFECT OF CASTRATION?
Yes, responses such as decreasing levels of aggression and a reduction in urine marking are indicative of the changes that surgical castration can bring about.

However hormone treatments can also have the effect of calming via the central nervous system.  Improvements in behaviour may be observed because of this rather than a change in hormone balance which makes determining the true effect of castration less than certain.

Some hormone treatments can cause dogs to become hungrier so if food guarding is an existing problem, it is best to avoid these.

Sometimes a veterinary surgeon will recommend hormone treatment as well as surgical castration to help calm the dog during the time it takes for neutering to become effective.  If the dog's behaviour regresses shortly after neutering, a repeat of the hormone treatment may be necessary.

THE RIGHT TIME FOR CASTRATION.
Castration can help alter a dog's behaviour at any age after puberty, but it is important to remember that castration will not have an overnight effect.  Improvement may take several months and inappropriate learned behaviours will need to be changed using behaviour modification techniques.

CASTRATION OF YOUNG MALE DOGS.
It is becoming increasingly popular to castrate male dogs at a young age, as a preventive measure.  The optimum time is just after the dog has reached puberty and started to lift his leg to urinate.  This is a policy which has been employed by Guide Dogs for the Blind for many years.

WHAT ARE THE DISADVANTAGES OF CASTRATION?
In some dogs, there may be coat changes that necessitate more frequent grooming to stop the coat matting.  In some short coated breeds the hair may appear to be thinner in places.

Some neutered male dogs become sexually interesting and are occasionally pestered by other males.  It is believed that after castration these dogs smell like a bitch.  In a survey of 98 castrated males, 23 owners reported this phenomenon immediately after neutering.  One year later the figure had reduced to 14 (Palmer).

WILL CASTRATION CAUSE MY DOG TO PUT ON WEIGHT?
No. However, after castration dogs can have an increased appetite leading the owner to give more food.  In this case weight increase is due to overfeeding not castration.  Many dogs do not need as much food to maintain their bodyweight after castration.  Reducing the diet at the first sign of weight increase will prevent problems.

I WANT TO TRAIN MY DOG TO WORK AND HAVE BEEN TOLD THAT CASTRATION WILL MAKE HIM LETHARGIC.  IS THIS TRUE?
No. In fact castrated males are frequently easier to train than entire males as they are less distracted.  Lethargy will not occur unless he is allowed to put on weight.

MY HUSBAND IS AGAINST CASTRATING OUR DOG.  HOW DO I CONVINCE HIM?
This is a common reaction due to what Freud called "castration anxiety", vicariously placed on the dog.  Most men think of their own sex lives, cross their legs and grimace if the topic is discussed!  They will, however, have female cats and bitches spayed and accept sterilisation in their wives.

Significantly, it is normally men rather than women who worry that castration will turn their macho male dog into a wimp! ( It won't! ) Hopefully the information on the preceding pages will counter this anxiety with rational thinking.