Sterilisation (Dog)


It is often a difficult decision as to whether to have a dog or bitch sterilised – we aim to answer the common questions and guide you in your choice. There are many factors to consider, so if you are still undecided after reading this leaflet, please ask one of our staff for advice.




Males (castration)

  • Prevents tumours of the testicles – these can also cause hair changes, lethargy, milk production etc.
  • Reduces the risk of prostate gland problems
  • Reduces occurrence of anal tumours and hernias near the rectum
  • Decreases sexual behaviour, aggression, dominance, roaming etc.


Females (spaying)

  • Reduces the risk of mammary tumours (the younger the bitch the greater the reduction in risk; in smaller dogs this is generally at 6 months and in larger dogs can be between 9-12 months)
  • Prevents tumours of the ovaries and uterus
  • Prevents pyometra (a potentially fatal womb infection)
  • No unwanted pregnancies or puppies
  • No false or phantom pregnancies, no milk production
  • Convenience – no male dogs sniffing around and no mess in the house



The procedure is carried out under a general anaesthetic. This always carries a very small risk, but we aim to minimise this by carrying out a clinical examination before we proceed; if indicated, we can carry out certain blood tests to help us identify specific risks that we can address. We use the safest anaesthetic agents we can and monitor each animal carefully to ensure a smooth anaesthetic and an un-eventful recovery.

In rare cases, there may be minor problems post operatively e.g. bleeding, suture reactions etc. and we deal with these accordingly.



Some dogs may gain weight after castration, but this can be controlled through diet and exercise. Many people are concerned that castration will alter the personality of their male dog; fortunately this is seldom the case as all castration does is remove the hormonal motivation for certain types of behaviour e.g. aggression, territorial behaviour but even these are unlikely to be affected if the males are older when they are castrated.



Some bitches may gain weight after spaying, but this can be controlled by careful diet and exercise. A very few may show some degree of incontinence, either just after surgery or years later. This can normally be controlled with medication or further surgery.




Neutering can be done from 6 months old. If one or both testicles are ‘retained’ (have not descended, and remain in the abdomen or groin), it if often wise to wait until the dog is 12 months old before castration, to give the testicle(s) a chance to descend.

Retained testicles have a dramatically higher risk of becoming cancerous and it is very important that they are removed. We may have to make one or more extra, larger, incisions to search for the retained testicle(s) and this does make the operation more complicated.


Neutering can be done either at around 6 months of age (before the first season), or about 2-3 months after the end of a season (there is a higher risk of bleeding if a bitch is spayed in season, and this is not recommended.)

A bitch with any of the following conditions should be allowed to have a season first:-

  • Any signs of pre-existing incontinence or urinary tract problems
  • Unusually small vulva (Infantile vulva)
  • Any discharge from the vulva (Juvenile vaginitis)



Sometimes we can tell by feeling for an old incision wound, or there are blood tests available to help answer this question.

In bitches, it can be worthwhile waiting to see if they have a season, but some bitches have a short, quiet seasons or very irregular seasons.

Alternatively, we may perform an ultrasound scan to see if we can visualise the ovaries or we may have to perform an exploratory operation to check for any ovaries or testicles.