What is neutering?

Neutering is the process whereby pets are surgically prevented from reproducing. In males the operation involved is termed ‘castration’; in  females it is called ‘spaying’. Both of these operations are performed under general anaesthetic.

When a male animal is castrated both testicles are removed, which takes away the main source of the male hormone testosterone. As the testosterone levels fall to a minimal level after castration, the effects of this hormone are also reduced.

When a female animal is spayed both the ovaries and the uterus (womb) are removed (ovariohysterectomy). This means that the animal is unable to become pregnant, and will no longer come into season.

Why you should have your cat or dog neutered?

There are several very good reasons to have your pet neutered.

For your pets health

  • Spaying female dogs (bitches) and cats, especially if this is carried outwhen they are young, will greatly reduce the risk of them getting breast cancers and infection of the womb (pyometra) – both of these are common and frequently fatal conditions in older, unspayed females
  • It should not be forgotten that both pregnancy and giving birth carry significant risks to the mother
  • In male dogs castration will significantly reduce the incidence of prostate disease, and reduce the risk of some cancers
  • Neutering male dogs and cats reduces their urges to roam and to fight - as a result they are less likely to go missing, get hit by cars, or suffer wounds from fights
  • For male cats, neutering reduces their chance of catching Feline Immunodeficiency Virus (FIV), an incurable viral disease, similar to HIV in humans, which is spread by saliva - most frequently from bite wounds while fighting
  • Pets which are not neutered and are confined can become frustrated and unhappy. They will often make determined efforts to escape and as a result may fall out of windows,go missing, or be involved in traffic accidents.
  • Many bitches will have a false pregnancy following their season. While this is natural, it can lead to behavioural problems and even, in some cases, medical ones Neutering will prevent this.

For your own sake

The decision as to whether to neuter your pet can affect more than the animal itself. If you’re thinking of not neutering your pet, you should consider the following.

  • For owners of unspayed female pets there is the permanent stress of ensuring that your pet does not become pregnant. If your pet does become pregnant, there is the added responsibility and worry of having to care for her through pregnancy, birth and the rearing  of her litter – before facing the challenge of finding good homes for the puppies or kittens. (You might want to reflect on the facts that a female cat can produce up to six kittens, three times a year, or that some breeds of dog can have as many as 12 puppies in a litter.)
  • Bitches in heat can be messy, producing a bloody discharge for three weeks or more, and attract a constant stream of hopeful male dogs to the front door. Female cats, if not spayed or mated, often come into season over and over again, so that they may be almost continuously on heat. This can be exhausting for both the cats and their owners, and usually attracts many amorous and vocal tomcats to the house.
  • Entire male cats will frequently urine-mark their territory with a powerful and unpleasant scented urine, not normally produced by neutered male cats. Bear in mind that they may consider your house part of their territory!
  • Male dogs have been known to break down doors and fences in their attempts to escape and go after bitches in heat. In the absence of a suitable companion, they are not too fussy about where they redirect their amorous intentions either, frequently mounting their toys, the furniture or their owner’s legs. They are also much more likely to show aggression to other dogs, whether on or off the lead.

To avoid unwanted litters

Every year many dogs and cats have to be put to sleep because there are more unwanted animals than there are homes available. This situation could be improved if more pet owners took the responsible decision to get their animals neutered.

When to have your cat or dog neutered

Both dogs and cats can be neutered from just ten weeks old, but most vets in the UK will neuter them when they are a little older.

  • For male cats, five to six months old is the most usual time of neutering, since after this age they will become sexually mature and capable of reproducing. However they may still be neutered safely when they are older than this.
  • A female cat can be neutered from four months or younger, as advised by your vet
  • Bitches can be spayed before their first season, from around six months of age, although for some of the larger breeds it is recommended that they be allowed to have one season first. Bitches should be spayed between their seasons, when the reproductive tract is dormant. It is better that bitches should be spayed before their third season, since after this time some health benefits are reduced.
  • For male dogs, the exact age that neutering is recommended varies slightly with the breed of dog, but most breeds can be neutered from six to seven months of age, with larger breeds of dog generally being neutered at a slightly later age than smaller breeds. Your vet will be able to advise you of the best time to get your pet neutered, but don’t leave it too late!

Frequently asked questions

Will my cat's or dog's personality change if I get them neutered?

No, but some unwanted behaviours may be reduced, such as roaming, mounting, fighting or urine spraying.

What about the risks of surgery during neutering?

Every surgical procedure carries a small degree of risk, but modern anaesthetic and surgical techniques are very safe. The risks, both short and long term, from not neutering your pet – from cancers, fighting, road accidents and unwanted pregnancies – are greater than those associated with neutering.

Isn’t it painful for your cat or dog to be neutered?

All surgical procedures involve a degree of discomfort, but neutering is carried out under a full general anaesthetic and animals are given drugs to control any discomfort afterwards. Most animals are up and about just a few hours after the surgery.

Should I let my cat or dog have one litter before having her neutered?

No. This is a common fallacy – there is no good reason for letting your pet have one litter before she is spayed. Dogs and cats do not form a lifelong bond with their offspring like people do, and do not miss the experience.

Can I still show my dog?

Yes. Changes in the Kennel Club regulations mean that neutered pedigree dogs can be shown.

Will my cat or dog get fat after being neutered?

No, your pet shouldn’t get fat. Neutered animals may have slightly lower food requirements than those which are entire, and should be fed slightly less accordingly.

How much will neutering my cat or dog cost?

This will vary depending on what sex and type of animal you have, and to some extent between vets. It is something you should discuss with your veterinary surgeon, ideally before you even get your pet. 

How much will not neutering my pet cost?

Bringing up a litter of puppies or kittens is an expensive business – in many cases the costs of feeding these extra mouths alone will be higher than the cost of neutering. Furthermore, if there are any complications with either pregnancy, birth or with the puppies or kittens afterwards, the veterinary costs can be very substantial indeed. Many charities can offer subsidised or discounted neutering schemes if you are eligible.

— Page last updated 10/03/2023