Neutering is the surgical removal of the reproductive organs, the testicles in the male animal ( castration ) and the uterus and ovaries in female animals ( ovariohysterectomy or spey ).

These operations bring about a number of changes in addition to rendering the animal infertile –

Effects on male animals

  • no longer show signs of territorial marking behaviour
  • testosterone induced aggression and/ or dominance is reduced (be aware that learned behaviours don’t change)
  • not interested in females who are in season

Effects on female animals

  • no longer show signs of being in season
  • the risk of developing uterine infection (‘Pyometra’) is reduced to zero ( though in rare cases it is possible to develop a ‘stump pyometra’ in the remaining part of the uterus around the cervix )
  • significantly reduced risk of mammary cancer in female dogs speyed before their first or second season ( this risk has been calculated to be about 1 in 1000. The risk for an entire female dog is 1 in 2! )
  • no lactation or behavioural changes due to false pregnancy

Why neuter?

Entire tom cats will range up to 3-4 miles to find a queen in season, putting them at markedly increased risk of being injured in fights, accidents on the road & contracting viral diseases such as FIV & FeLV. They can potentially sire many hundreds of kittens every year. And of the course the pungent smell of tom cat an be quite overwhelming to live with!

In male dogs neutering is recommended to prevent uncontrolled reproduction ( again, male dogs will wander to find a bitch in season, some may actually become distressed and off their food if they sense one nearby ), as a supportive measure for some behavioural issues ( but not all, care must be taken as neutering fearful or anxious dogs may exacerbate the problem ), and as a treatment for conditions such as prostate problems, perineal hernias, testicular tumors (especially in retained testes ‘cryptorchidism’, where one or both testes has remained inside the abdomen ) or peri-anal tumours.

In female cats and dogs there are the health benefits mentioned above, prevention of unplanned pregnancy &also prevention of false pregnancy ( which can affect some animals physical & psychological well-being quite significantly ). In addition, some medical conditions may deteriorate due to the hormonal changes around the time of the season eg epilepsy, diabetes and fox mange.

Are there reasons not to neuter?

Due to the hormonal changes after neutering, the “basal metabolic rate” decreases, meaning most animals require fewer calories to maintain their weight. A small consistent reduction in food intake will prevent weight gain.

Large breed dogs (eg GSDs, Dobermans and Boxers), may be slightly more suspectible to developing urinary incontinence after speying. Waiting for full maturity to be attained, & a small adjustment to the length of uterus removed during surgery can help reduce this risk. There are also effective medications which can control this problem if it does develop.

In some cases, speying may lead to the formation of a slightly softer coat in long-haired breeds (eg Setters, Spaniels )

Some behaviours in male dogs may not respond positively to castration. There is the option of trialling with a form of medical castration first to gain some idea how surgery may affect these patients eg Tardak injection ( lasting 3-4 weeks ), Suprelorin implants ( like a microchip – last 6 or 12 months ).

When to neuter

For cats of both sexes we would recommend around 5.5 – 6 months old, but it can be done earlier if a cat shows signs of becoming sexually mature before then ( increasing day length going into Spring will stimulate hormonal development )

For male dogs, as a routine we would suggest around one year of age, possibly older for larger breed, slower maturing dogs, or a bit earlier if testosterone influenced behaviours become prominant.

Advice is given on an individual patient basis for female dogs. The average age for coming into season for the first time is 9 months old, a little earlier for small breeds & later for large. We are happy to spey dogs at around 7-8 months of age, prior to their first season, if they are physically mature enough. Otherwise, we would recommend 2-3 months after their first season as a general rule.

We are always happy to discuss an individual patient’s needs. Although overall neutering is highly recommended, it is not a case of ‘one size fits all’, & there can sometimes be a number of factors to consider in assessing a pet prior to surgery. Get in touch today.


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