World Spay Day: Make a difference through desexing

The overpopulation of companion animals is one of the biggest issues SPCA and animal welfare organisations across Aotearoa face. Every week, litters of unplanned, vulnerable animals come through SPCA’s doors, the pitter-patter of tiny paws seemingly endless for our teams at SPCA Centres.

It’s an uphill battle and desexing is one of the key ways we can combat this problem in our communities, break the cycle of unwanted litters, and ultimately prevent animals being born into a life of cruelty and neglect. One tiny snip can make a world of difference and this World Spay Day, we’re shining a light on the benefits this vital procedure has for improving animal welfare in Aotearoa New Zealand.

Read on for answers to your frequently asked questions.

What is desexing?

Desexing is the surgical removal of part of the animals’ reproductive system. Under New Zealand legislation, this is a significant surgical procedure and must only be undertaken by a veterinarian, or a veterinary student under the supervision of a veterinarian.

There are many different words to describe this procedure (desexing, spaying, neutering, altering, castration, sterilisation etc.), but they all refer to the surgical altering of an animal to prevent breeding.

Other than preventing breeding, what are the advantages of desexing?

• Prevents false pregnancies in females.

• Eliminates “heat” cycles in females, which is often inconvenient for owners.

• Reduced roaming activity (in search of mates) - meaning they are also less likely to be hit by a car, or become sick from infectious diseases and parasites.

• Less chance of developing certain kinds of cancers.

• Eliminates the chance of common uterine infections (in females).

• Reduces fighting and aggressive behaviours which reduces risk of contracting infectious disease spread by fighting.

• Reduces dominance aggression and fighting between individual rabbits, thus making them easier to house together.

• Reduces unwanted animals being attracted to your property by females in heat.

• Reduces dog registration fees.

• Reduces urine and scent marking behaviour.

• Reduces territorial aggression towards owners in rabbits.

• Desexed animals generally live longer, healthier, happier lives due to various health benefits, some of which are listed above

Should I desex my companion animal?

Yes! SPCA advocates for all companion cats, dogs, and other companion animals as deemed appropriate, to be desexed except registered breeding animals. Desexing is an important component of population control and has welfare benefits for the desexed animal.

At what age should my companion animal be desexed?

SPCA supports pre-pubertal desexing - that is desexing before the animal reaches puberty and is able to reproduce. We recommend that all cats, dogs, rabbits, and other companion animals are desexed as early as possible in accordance with veterinary advice.

What about small animals (rabbits, guinea pigs, rats, mice) – can they be desexed?

SPCA supports the pre-pubertal desexing of all companion animals, and recommends that rats, mice, rabbits and guinea pigs be desexed as early as possible in accordance with veterinary advice.

Not all veterinarians will offer desexing services for rabbits and small rodents. Ask your veterinarian, your local SPCA, or rabbit/rodent society/interest group for recommendations for a veterinarian who does offer desexing for rabbits/rodents and is experienced and familiar with anaesthetising and desexing these small animals.

Fun fact - male rabbits can still be fertile for up to six weeks post-desexing, so bear this in mind when considering housing arrangements during this time.

Will desexing change my dog's nature?

There is generally no great character change noted after desexing, although a dog may be quieter, more placid, and less likely to roam.

Should my female dog or cat have a litter before being desexed?

No! Well-meaning people may tell you that your female dog or cat should have a litter or experience a heat cycle/season before she is desexed. However, veterinary science tells us that the opposite is true!

Female animals that have not been desexed are at higher risk of developing cancers of the uterus, ovaries and mammary glands, as well as suffering from complications of pregnancy and birthing.

Will desexing my dog make him/her gain weight?

Desexing removes the animals’ major source of sex hormones which can slightly lower the metabolic rate. As a result, a desexed animal may be at risk of gaining weight more easily, but only if you feed him/her more than needed. Our advice is to ensure your desexed companion animal is fed a nutritious diet and regularly exercised appropriate for their age, size, and any health conditions.

When should my male horse be castrated?

Male horse castration is a routine surgery that is performed to prevent unwanted offspring and possible health or behavioural issues. We recommend that you discuss the best timing for this procedure with an experienced equine veterinarian. You can ask your local SPCA or horse society/interest group for recommendations if you do not already know a suitable local veterinarian.

I want to get my animal desexed, but I can’t afford it – what should I do?

Certainly, there is a cost involved and this can be a barrier for some people to get their animals desexed. Fortunately, the cost of desexing is a one-off expense and there are many initiatives that offer lower cost (sometimes free) desexing for people who can’t afford normal veterinary fees. We recommend comparing prices with veterinary clinics in your area, and checking if any offer discounts or payment plans. You can keep an eye out for SPCA Desexing Services in your area on our desexing website.

Desexing every animal adopted from SPCA care

Stopping the cycle of unwanted litters starts with us. SPCA ensures that every animal adopted from our Centres goes into their forever home desexed. In 2025, we desexed over 13,130 animals in our Centres!

This litter of kittens are just a few of the thousands that have come into SPCA’s care recently. Born on Christmas Day, they were brought into our Wellington Centre with gunky eyes – the owner was unable to afford vet treatment.

Receiving the treatment they needed, they were then placed into foster care to await their desexing surgery.

“They’re due to be desexed this week,” says Archie Pararasasingam, Wellington Centre Manager. “The importance of desexing can’t be emphasised enough. We’re so pleased to be able to do this for these kittens, to prevent more unwanted and vulnerable litters being born in the future.”

Offering discounted desexing to our communities

SPCA has invested heavily in making desexing services more accessible to pet owners through our discounted Snip ‘n’ Chip desexing and microchipping campaigns. In 2025, we desexed over 33,340 animals both in our Centres and out in the community!.

More Snip ‘n’ Chip campaigns will be launched in March/April of 2026, so keep an eye on our desexing site.

Bringing desexing services to those without

SPCA also has its Mobile Desexing Clinic – affectionately known as ‘Snippy’! This one-of-a-kind clinic on wheels travels to isolated communities where residents have difficult access to veterinary clinics, offering free desexing and microchipping services to struggling pet owners. Snippy targets to communities with a high population of stray animals.

Last year, the SPCA Mobile Desexing Clinic travelled to the isolated West Coast town of Karamea, where the team desexed 31 cats and eight dogs over just five days. We were thrilled to be able to make a real difference for a community in desperate need of it.

What you can do to break the cycle:

• If you’re looking at adopting, consider adopting from SPCA – all our animals come fully desexed, microchipped, vaccinated, and up to date on worming and flea treatment.

• Have your own companion animal desexed if you haven’t already!

• Ask your veterinarian about pre-pubertal desexing - why wait? Do it today!

• Encourage friends, family, and neighbours to have their animals desexed too.

• Support and even donate towards the desexing of shelter animals and stray cats in our communities.