Sterilisation
About sterilisation, its benefits, and misconceptions
Last updated 31 October 2025
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Surgical sterilisation of pets is important for reducing the number of unwanted litters.
Cats can breed from as early as 4 months of age, and about 6 months for dogs. A pair of fertile cats, together with their offspring, are capable of producing over 300 kittens in 4 years.
What is sterilisation?
Sterilisation, also known as neutering or desexing, is a surgical procedure in which a part of your pet’s reproductive organ is removed to permanently stop it from reproducing. Sterilisation is done generally on male and female dogs, cats, rabbits and guinea pigs.
Male animals are castrated through the removal of the testicles, and female animals are spayed through the removal of the ovaries and uterus. Sterilisation can only be performed by a licensed veterinarian under strict sterile conditions with the animal under general anaesthesia. Pet owners should consult their veterinarians to determine if their pets are fit for sterilisation.
Benefits of sterilisation
Sterilisation helps your pet lead a healthier life, as sterilised animals are less prone to certain diseases. Sterilising your pet also demonstrates responsible ownership towards your pet, your neighbours and the wider community.
Sterilisation prevents unnecessary breeding and reduces the number of unwanted animals.
Sterilisation reduces the risk of mammary gland tumours, ovarian and uterine cancers and womb infections (pyometra) in females, and testicular cancer and incidence of prostate disease in males.
For females, heat cycles will stop, and male attraction will cease or be significantly reduced.
Sterilisation also helps to reduce undesirable sexually-motivated behaviours such as mounting in dogs, and caterwauling (loud, yowling vocalisations), roaming, and spraying in cats.
Common misconceptions about sterilisation
Sterilisation is a painful and dangerous surgery.
Sterilisation is the most common surgery performed on animals. The risks are minimal when carried out by a licensed veterinarian. Your pet will not feel any pain as the procedure is performed under general anaesthesia, and painkillers will be provided as needed. Most pets recover quickly and return back to normal within 24 to 48 hours.
In very few cases, an older sterilised pet may lose some control of its bladder or experience thinning of its body coat. These are not serious conditions and can be easily resolved with medication.
Sterilisation causes obesity.
Weight gain is typically due to overfeeding, a lack of exercise, or underlying health issues – not sterilisation.
Contrary to popular belief, sterilisation brings multiple behavioural benefits. Given their reduced desire to mate, sterilised cats are less likely to roam, caterwaul (howl loudly) and mark their territory with a pungent urine spray. Sterilised male cats are less likely to fight, reducing the risk of cat bite infections and infectious diseases such as Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV).
Sterilised cats are calmer and easier to manage – your neighbours will thank you too.
Sterilisation is costly.
Sterilisation is a one-time procedure that lasts your pet's lifetime. The cost of sterilisation is minimal compared to the expense of raising a litter of offspring. Additionally, sterilisation can be considered an investment, as sterilised pets are less prone to certain illnesses, potentially reducing future veterinary costs.
Kittens are too young to breed.
Cats can breed from four months of age and produce up to four litters annually. A female cat will give birth about two months after becoming pregnant. An unsterilised pair can multiply very quickly and overwhelm your capacity for care.
Sterilisation cannot be performed on kittens.
Healthy cats can be safely sterilised by a licensed veterinarian once they weigh about 1kg, which is typically just over two months of age – such early-age neutering is commonly practised in shelters for population control.
For pet cats, sterilisation is recommended by four to six months of age. The “Fix by Five” guideline is endorsed by the World Small Animal Veterinary Association (WSAVA) and the American Veterinary Medical Association (AVMA). The Australian Veterinary Association (AVA) advocates sterilisation of cats before four months of age. While sterilisation by six months of age was previously recommended, veterinary associations worldwide now support earlier sterilisation to prevent unwanted litters and to maximise health benefits. Younger cats are also likely to recover more quickly from surgery than older cats.