At The Natural Vets our aim is to provide you with the best and most up-to-date advice to ensure your animal’s health and vitality is supported.

Most owned cats and dogs in Australia are speyed or castrated before 1 year of age, usually around 5-6 months of age when they are still very much a juvenile.  In shelter environments desexing is performed as young as 6 weeks of age in some animals. Desexing has been advocated as a form of population control, and considered necessary to prevent problems like mammary tumours and pyometra (uterine infections) in intact females, and aggression and benign prostrate growth in intact males.

A wealth of evidence is mounting, however, that suggests preserving sex hormone production, especially in the first few years of life, is beneficial for pets long-term, whereas the risk of pyometra, prostate disease or mammary cancer in their early years is incredibly low.  

A number of studies have demonstrated links between early neutering (before maturity) and the following problems:

  • debilitating endocrine diseases such as Cushing’s, atypical Cushing’s and thyroid disease
  • cruciate ligament ruptures
  • hip dysplasia
  • abnormal bone growth and joint conformation problems
  • bone cancer
  • cardiac tumours
  • lymph cancer (lymphosarcoma)
  • blood cancer (haemangiosarcoma)
  • mast cell tumours
  • urinary incontinence
  • higher incidence of adverse vaccine reactions
  • increased incidence of some behaviour issues such as fears and phobias
  • increased risk of infectious disease
  • shortened lifespan (not surprising given all of the above!)

Desexing your pet before skeletal growth and sexual maturity is complete significantly increases the risk of all the above conditions.

Reasons pronounced for desexing your pet at a young age include a higher risk of mammary cancer and uterine infections in females left entire, and behavioural issues such as dominance aggression in male dogs.  If you desex after your female dog has had one or two heat cycles, the risk of mammary cancer is still extremely low, and it is unlikely that a uterine infection will develop at such a young age prior to desexing.  Intact males have a higher risk of benign prostatic enlargement, but this is highly responsive to desexing at the time of diagnosis.  More aggressive prostate cancer is of equal risk in entire and desexed males.

The health ‘risks’ commonly thought to be associated with keeping ovaries in a female dog include pyometra, which is infection of the uterus, and mammary tumours. The risk of pyometra can be avoided by perfoming an alternative spey procedure where the ovaries are preserved but the entire uterus and cervix is removed (a hysterectomy), or by performing the usual ovariohysterectomy where both ovaries and the uterus are removed, after your female has reached maturity.  Mammary cancers were thought to be more common in dogs speyed after their second heat cycle, however, recent studies have been unable to validate the theory that early spaying protects female dogs from mammary cancer.  

In male dogs, there is a belief that neutering before puberty is necessary to prevent problem behaviours such as urine marking in the home or aggression toward the owners.  Most intact males who are properly socialised, trained and handled will not develop behaviour problems, however, and certainly won’t wee in your house.  And if testosterone-related problems do develop, research shows that neutering males in adulthood is as effective in changing the behaviour as neutering before puberty is in preventing the problems.

Certainly some male dogs may benefit from earlier desexing, particularly if they are around entire female dogs on heat which quite frankly sends them crazy!

So what is the alternative?

Sterilisation is the best option for individual animals.  It is very important that all dogs not intended for breeding should not be bred.   But we also want every pet to experience optimal health, wellness and longevity, and delaying desexing can help them achieve this.

In most situations it is best to delay desexing, until after your dog has reached adulthood.  In most dogs this is 12 months of age, but some large and giant breeds aren’t considered fully grown until two years of age. Cats are faster maturing, and so desexing at 6 months of age is still considered to be appropriate for them.

For people wanting to preserve the gonads but sterilise the animal (for example breeders who choose to sterilise their pets prior to adoption) we offer gonad-sparing sterilisation procedures (hysterectomy which is also called ovary-sparing spey, and vasectomy procedures).