Neutering your cat: when, why and how

Neutering your cat is a medical, ethical and practical decision with broad veterinary consensus: virtually all vets recommend neutering domestic cats. This guide covers why, when and how it's done.

Why neuter?

Neutering (also called castration in males, spaying in females) removes the ability to reproduce and has additional hormonal effects that are positive for health and behaviour.

It's standard for domestic cats for 4 main reasons:

• Feline overpopulation · there are hundreds of thousands of homeless cats. Every litter makes the problem worse.
• Medical benefits · reduces mammary cancer by up to 80% in females, eliminates testicular cancer in males and the risk of pyometra (fatal uterine infection).
• Better behaviour · no territorial marking, no heat calling, fewer fights, less running off to look for a mate.
• Longer life expectancy · neutered cats live 3-5 years longer on average.

Medical and behavioural benefits

Medical benefits in females:

• 80-90% reduction in the risk of mammary cancer (if performed before the first heat)
• Elimination of the risk of pyometra (uterine infection, fatal without urgent surgery)
• Elimination of ovarian and uterine cancer
• Elimination of phantom pregnancies and birthing problems

Medical benefits in males:

• Elimination of testicular cancer
• Reduction of prostate tumours
• Fewer fights, fewer injuries, and lower risk of FIV/FeLV (which are transmitted through fights)
• Less roaming and fewer road accidents

Behavioural benefits:

• No heat calling (females can spend 4-7 days calling intensely)
• No territorial urine marking (a serious problem in flats)
• No heat-related aggression
• Calmer, more affectionate, and more sociable

Optimal age: 5-6 months

Current veterinary recommendation is to sterilise between 5 and 6 months, before the first heat. In females, this timing is crucial because the earlier it is done, the greater the reduction in the risk of mammary cancer.

Early sterilisation (3-4 months) is safe and is performed in TNR (Trap-Neuter-Return) protocols for controlled colonies. It requires a veterinarian experienced with small kittens.

If your cat is already an adult, it’s not too late. Neutering at any age is better than not neutering. The cancer-prevention benefits are smaller, but the behavioural benefits (spraying, aggression, roaming) remain significant.

Male vs female: what's different

In the male (castration):

• Surgery: 10-15 minutes. The testicles are removed through the scrotum.
• Short general anaesthetic.
• No external sutures in many cases (internal layered closure).
• Recovery: 5-7 days. Returns to almost normal activity in 48h.
• Cost: €40-90 at a private practice.

In the female (spay):

• Surgery: 20-30 minutes. Ovaries and uterus are removed (or only ovaries if laparoscopic).
• Longer general anaesthetic.
• External or intradermal sutures. Cone/buster collar for 7-10 days.
• Recovery: 10-14 days, avoiding jumping and running.
• Cost: €70-130 at a private practice.
• Some clinics offer laparoscopy (less invasive, 5-7 day recovery) for +€40-70.

The surgical procedure

Step by step, what happens on the day of surgery:

1. Prior fasting: no food 8-12h before (water allowed until 2h before)
2. Arrival at the clinic: pre-anaesthetic check · auscultation · weighing · optional blood test (recommended for cats over 5 years)
3. Pre-medication: sedative + pain relief
4. General anaesthetic: typically intubation + anaesthetic gas (sevoflurane or isoflurane)
5. Surgery: 10-30 min depending on sex
6. Waking up: 30-60 min in a recovery cage with a heat mat
7. Discharge the same day: you collect them in the afternoon with pain-relief medication to take home

The mortality risk is low in healthy young cats. It increases in obese cats, those over 10 years old, or those with pre-existing conditions.

Post-operative recovery

First 24 hours:

• A quiet spot, no stairs or jumping
• A light meal in small amounts once fully awake
• A cone/buster collar to stop it licking the wound
• Oral pain relief as prescribed by the vet

Days 2-7:

• Watch the wound: redness, swelling, discharge = call the vet
• No baths, no going outdoors, no contact with other cats
• Limit sudden movement
• Check-up at 7-10 days to remove stitches (if any)

Normal symptoms: drowsiness for the first 12-24h, reduced appetite for 24-48h, slight swelling at the surgical site.

Red flag, call the vet immediately: fever, repeated vomiting, open wound, active bleeding, not urinating within 48h, extreme pain, pale gums.

Cost and where to get it done

Options from lowest to highest cost:

• Charity and council-backed neutering schemes · €0-30 · Charities such as Cats Protection or the RSPCA, often with local councils. There's usually a long waiting list (3-6 months).
• Rescue charity arrangements · €30-70 · If you adopted, many rescue charities offer neutering at an agreed rate at their partner clinic.
• Low-cost clinic · £50-85 male / £70-110 female · Variable quality, check reviews.
• Standard private practice · €70-120 male / €110-170 female · Full service with pre-anaesthetic blood work + post-op check.
• Clinic with laparoscopy · €180-280 female · Less invasive, faster recovery.

Vets in the Mizuu network offer competitive rates and the procedure is recorded in the cat's digital passport (including any complications or particulars).

Common myths debunked

"She has to have at least one litter before being neutered" · FALSE. It's a myth. There is no benefit to having young before neutering. On the contrary: every litter increases medical risk and worsens overpopulation.

"It becomes fat and lazy" · PARTLY. The metabolism drops by 20-30%. If you adjust the diet, it won't gain weight. "Lazy" = calmer, which isn't a flaw.

"We're taking away its masculinity/femininity" · A HUMAN CONCEPT. Cats don't have that kind of identity. Without hormones, they're simply less stressed by being in heat.

"It's very expensive" · COMPARED WITH WHAT. The cost of a litter (the mother's vet care, kitten vaccinations, neutering the kittens, 2 months of food) exceeds €400-800. Neutering is the economical option.

"My cat doesn't go outside, it doesn't need neutering" · FALSE. Females still come into heat (intense calling every 2-3 weeks), males still mark with urine, and both still carry the risk of hormonal cancer.

In short: neuter your cat between 5-6 months (before the first heat) at a vet you trust. Cost €40-130 depending on sex. Recovery 1-2 weeks with basic care. The medical and behavioural benefits far outweigh the cost and the one day of discomfort. If you adopted, it probably comes already neutered.