Whether or not to spay or neuter one’s dog and when to do it can be a bit of a contentious issue. Some people have very strong opinions on the matter and others seem indifferent. To confuse matters even more, there are many old wives tales about the effects of castration or spaying. I am sure you have heard the following:
a) My dog will behave like a wimp if he is neutered.
b) My dog will not develop properly if he is neutered.
c) My dog won’t be a good guard dog if he is neutered.
d) It would be good to have just one litter for the kids to learn about life.
e) It will calm my dog down if I let her have a litter before I spay her.
f) It will be healthier for my dog if I let her have a litter before I spay her.
g) My dog will get fat if he/she is neutered.
The truth is that there is very little evidence to support any of the above statements and quite a lot of evidence to refute most of them. What follows is a reasonably in-depth discussion of the facts about neutering which will hopefully allow you to make an informed decision in this regard.
What is spaying or neutering?
In short, spaying or neutering a dog involves the removal of those organs which produce the majority of the sex hormones and which are involved in reproduction. In male dogs the testes are removed and in females the uterus and ovaries are removed. This is usually done at around six months of age, before dogs reach sexual maturity.
What makes a dog a dog and a bitch a bitch?
While puppies are still in the womb, a surge of testosterone reaches the male puppies’ brains, bringing about gender-specific structural changes which enable the development of sex-typical behaviours (O’Heare, 2006). At puberty (beginning at 4 - 5 months of age) the testosterone levels of male dogs’ begins to rise, increasing the frequency and intensity of male behaviours. Even if the source of testosterone is removed at this point, the dog will retain typical male behaviours to a certain extent, because its brain was pre-programmed to be male before birth.
Females do not receive a surge of testosterone in utero and their brains therefore develop as female. Once female dogs reach adolescence (anything from 6-10 months of age), estrogen and progesterone bring about the female heat cycle and influence behaviours related to reproduction, such as nest building. Once again, removing the source of these hormones at adolescence will not stop the dog from being female.
What are the behavioural benefits of castrating a dog?
The rise of testosterone at adolescence makes dogs more likely to engage in sexually related behaviours which may make them difficult to live with. Mounting dogs or people, competing with other male dogs (leading to fights), excessive urine marking and escaping from the property to roam are all behaviours which are influenced by testosterone. Studies have shown that castration typically reduces these behaviours as follows:
Mounting of people: reduced in 60% of cases
Urine marking in the house: reduced in 50% of cases
Intermale aggression: reduced in 60% of cases
Roaming: reduced in 90% of cases
(Fogle, 1990, p.53)
These statistics apply to dogs that are already exhibiting these problem behaviours. The retention of the behaviours in some dogs after castration is likely due to the fact that the behaviours have taken on a learned component and are no longer due only to hormones. Dogs that are castrated at adolescence, before these behaviours start, are less likely to develop them in the first place.
It is also possible that rising testosterone levels cause young males to be targeted by other dogs so that they will learn ritualised competitive male behaviours. (Dunbar, 1999, pg 68) This means that even if your dog is not interested in fighting, he may be picked on regularly by other male dogs and end up having unpleasant social experiences which may negatively influence his attitude towards other dogs in the end.
What are the behavioural benefits of spaying a bitch?
Spayed bitches are far less likely to exhibit behaviours associated with the increased level of progesterone which remains in the dog’s body for two months after the heat cycle. Therefore spaying should prevent unwanted behaviours such as nesting, false pregnancies, guarding of objects (the dog behaves like your sock is a puppy, carries it everywhere and protects it like mad), irritability, increased competition with other females and lethargy.
Is there ever any behavioural reason not to spay or neuter?
Very occasionally some dogs may benefit behaviourally from being allowed to reach sexual maturity. I have found that when a male dog has an extreme lack of confidence as a puppy, the increase in testosterone at puberty seems to increase the dog’s confidence to a certain extent and may therefore make him less likely to exhibit fear aggression. However, I do not know of any studies which support this anecdotal evidence. (It must also be born in mind that continued socialising is probably also a factor in the improvement that I have noticed in such dogs.)
When it comes to bitches, research (O’Farell & Peachey, 1990) has shown that spaying a bitch before she is 12 months of age, may result in an increased level of control-type (”dominance”) aggression towards family members. Note that this is only in bitches that are already exhibiting this type of aggression in the home. This may be due to the fact that by removing the source of female hormones, testosterone levels in bitches are now relatively higher. However, the same research shows that bitches spayed after a year of age are not negatively affected. Thus, if aggressive behaviour is already a concern, spaying should simply be delayed until 12 months of age. (In this case it is also best to spay only once the progesterone levels have normalised after the heat cycle i.e. over two months after the heat cycle).
In respect to this, it really must be noted that due to the very unfortunate information given out by popular “dog psychologists” with no real training, “dominance” aggression is blamed for just about every behaviour under the sun. In most cases there are other less “trendy” reasons for behaviours categorised in this way and spaying a bitch will not be detrimental in any way.
Health benefits of neutering
Bitches that are spayed before their first season will not develop cancer of the uterus or pyometra and are less likely to develop breast cancer. Castrated dogs will not develop testicular cancer and are less likely to develop prostrate disease (ASPCA’s Complete Guide to Dogs, 1999, pg 75, 482)
At what age should I neuter my dog?
The usual age at which both male and female dogs are neutered is 6 months. At this stage the male dog’s hormone levels have already started to rise, but associated behaviours may not yet have begun or will not yet be entrenched. Spaying females at this age prevents them from entering their first heat cycle which may occur at any time from this age onwards.
Some welfare organisations neuter much younger, but as this is a fairly new practise, it is not certain yet what the implications are for a dog’s long term health and development.
But I just want to let my dog have one litter!
While my attitude may seem harsh, I strongly believe that unless you are a registered breeder or intend to become one, you have no right to breed with your dog. There are so many unwanted puppies and dogs in shelters and every unregistered puppy you produce takes away a potential home from one of these animals.
Registered breeders are required to uphold certain breed, health and ethical standards. These requirements make breeding a serious and often costly business. Before a mating takes place, bloodlines must be researched, health- checks must be made and potential mates must have reached a suitable age for reproducing. Good breeders will also know how to correctly socialise puppies until they are homed. Are you ready to undertake all these requirements?
I don’t want my dog to get fat
Many people blame neutering for their dogs’ weight problems. However, in most cases those same people over-feed and under-exercise their dogs. While neutering in both males and females may lead to an increase in appetite, regular exercise and a healthy and controlled diet will ensure that dogs do not become obese.
It must be remembered that while neutering generally has many behavioural benefits, it is not a cure all and should never replace proper training and socialising.
References:
1. James O’Heare: The Effects of Spaying & Neutering on Canine Behaviour, www.jamesoheare.com, 2006
2. Bruce Fogle: The Dog’s Mind, Howell Book House 1990
3. Ian Dunbar: An Owners Guide to Healthy Happy Pet Dog Behaviour, Howell Book House, 1999
4. O’Farrell & Peachey: Behavioural effects of Ovariohysterectomy on Bitches, Journal of Small Animal Practice, 1990
5. ASPCA’s Complete Guide to Dogs, Chronicle Books, 1999