Will my cat definitely gain weight after being spayed or neutered?

Not necessarily, but there is a tendency. Spaying/neutering lowers sex hormone levels, which also play a role in metabolism regulation. A cat's caloric needs drop by around 20–30% after the procedure. If food portions are not adjusted, weight gain can occur. Solution: reduce portions by about 20%, choose "indoor" or "neutered" formulas with lower calories, and ensure the cat stays active with play.

Does spaying/neutering make cats or dogs lazy and inactive?

This is largely a myth. Changes in behaviour after sterilisation are mainly related to reproductive drives: less aggression, no urine spraying, no more loud vocalising during heat. Play activity and curiosity do not disappear if the owner continues to provide toys and interaction. Pets that seem "lazy" after sterilisation are usually understimulated — not affected by the procedure itself.

Does spaying/neutering change a cat's or dog's personality?

Sterilisation reduces behaviours driven by reproductive hormones — aggression between males decreases, urine marking reduces, and heat-related restlessness disappears. Core personality traits (active/lazy, affectionate/independent, timid/bold) do not change, as personality is shaped by genetics and environment, not reproductive hormones.

Does a female cat need to give birth once before being spayed?

No — this is a scientifically unfounded myth. There is no proven health benefit to letting a cat give birth once before spaying. In fact, the opposite is true: spaying before the first heat cycle (around 5–6 months) provides the best protection against mammary cancer.

Can spaying cause urinary incontinence in female dogs?

Urinary incontinence is more common in spayed female dogs (especially large breeds), occurring in approximately 5–20% of cases. This condition is called USMI (urethral sphincter mechanism incompetence) and can be managed with vet-prescribed medication. Despite this risk, the overall benefits of spaying still far outweigh it.

Side Effects of Spaying/Neutering Cats & Dogs: Facts vs Myths (2026 Guide)

"I'm afraid to have my pet spayed or neutered because I've heard so many bad things about it." This is one of the most common things we hear from pet owners. The concern is understandable — but much of what circulates are myths, not medical facts.

This article is an honest look at: the real benefits of sterilisation, the side effects that genuinely exist (and how to manage them), and the myths that need to be set straight.

Scientifically Proven Benefits of Sterilisation

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For Females

Eliminates mammary cancer risk: Spaying before the first heat cycle reduces the risk of breast cancer by up to 99.5%. After 2 heat cycles, this protection decreases significantly.
Prevents pyometra: A life-threatening uterine infection that can affect up to 25% of unspayed cats/dogs over 10 years of age.
Eliminates heat cycles: No more restlessness, loud vocalising at night, or attention-seeking behaviour toward males.
Prevents unwanted pregnancy: Helps control the pet overpopulation problem.

For Males

Eliminates testicular cancer: Cannot develop cancer in organs that no longer exist.
Reduces prostate risk: Benign prostate enlargement is very common in older intact male dogs.
Stops urine marking: The habit of spraying urine to mark territory is drastically reduced.
Reduces inter-male aggression: Fighting with other male cats/dogs decreases significantly.
Reduces roaming: Searching for females in heat is the leading cause of pets escaping.

Real Side Effects (and How to Manage Them)

Tendency to Gain Weight

Real. Metabolism slows by around 20–30%. This does not mean weight gain is inevitable — it just requires adjusting food portions.

Preventable

Solution: Reduce portions by 20%, choose "neutered/indoor" formula food, add 15–20 minutes of active play per day.

Urinary Incontinence (Large-Breed Female Dogs)

Occurs in approximately 5–20% of spayed large-breed females. Presents as leaking urine during sleep or after running.

Manageable

Solution: Low-dose oestrogen or phenylpropanolamine prescribed by a vet is effective for this condition.

Surgical & Anaesthetic Risk

As with all surgical procedures, risks exist — anaesthetic reaction, bleeding, post-operative infection. In young healthy animals, the risk is very low (<0.1%) at clinics with good standards.

Low Risk

Myths That Need Correcting

"Cats/dogs must give birth at least once before being spayed"

No scientific basis. In fact, spaying before the first heat cycle provides the best protection against mammary cancer.

"Sterilisation makes animals unhappy because they lose a natural instinct"

Animals do not have the same conscious awareness of reproduction as humans. Heat is a hormonal response that frequently causes stress and frustration — not an experience that is "missed" once it is gone.

"Sterilisation changes the animal's personality"

Core personality is shaped by genetics and environment, not reproductive hormones. What changes is only behaviour driven by heat and sex hormones.

"Sterilisation shortens the animal's lifespan"

The opposite is true. A large US study (Banfield Pet Hospital, 2013, n=460,000 animals) found that neutered male cats lived 62% longer, and spayed females 39% longer, than their intact counterparts.

What Is the Best Age to Spay or Neuter?

Cats

Male: 6–8 months (before spraying starts)
Female: 5–6 months (before first heat cycle)
Best mammary cancer protection: before first heat cycle

Dogs

Small-breed male: 6–9 months
Large-breed male: 12–18 months (wait for bone development)
Female: 6 months or after first heat cycle is complete

Still Unsure? Get a Free Consultation First

Ask all your questions about sterilisation directly to our vet via WhatsApp — at no cost. We will help determine the right timing and the right facility for your pet.

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Side Effects & Benefits of Spaying/Neutering Cats & Dogs: Facts vs Myths

Scientifically Proven Benefits of Sterilisation

For Females

For Males

Real Side Effects (and How to Manage Them)

Tendency to Gain Weight

Urinary Incontinence (Large-Breed Female Dogs)

Surgical & Anaesthetic Risk

Myths That Need Correcting

What Is the Best Age to Spay or Neuter?

Still Unsure? Get a Free Consultation First

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