Desexing Your Pet – Benefits & Best Age

There are more animals than the number of responsible homes available at any one time.
Last year the RSPCA alone received over 90, 000 unwanted dogs and cats.

What are the benefits?

  • Reduces the number of unwanted puppies and kittens
  • Behaviour management –
    • Desexed dogs are more likely to stay at home and less likely to fight.  If they’re scared, they might growl or bite (fear aggression), but they are less likely to pick a fight.
    • Urine spraying and mounting are associated with the sex hormones, and so occur less commonly in desexed animals.
  • Health benefits
    • Pyometra, a disease of the uterus, can occur in female dogs after heat when no pregnancy results.  The uterus is usually removed at time of desexing, and so pyometra isn’t seen in desexed female dogs.
    • Cancers of the prostate, anal region and mammary tissue are often associated with the sex hormones.  Desexing reduces the risk of these cancers.
  • Desexed dogs and cats have a longer, happier life.

What age should my dog be desexed?

Small breed dogs reach puberty and come into heat earlier than larger dogs, usually at 6-7 months age but sometimes a few weeks earlier when only 5 months age.  Medium breed dogs usually come into heat after 7 months age, large and giant breed dogs usually come into heat after 9 months age.

Age of desexing is a balance between the benefits of desexing and enabling optimum growth and strong healthy joints. Recent studies suggest  that early desexing of large dogs might be contributing to developmental joint diseases such as elbow dysplasia, hip dysplasia, cruciate ligament disease.  Dachshunds desexed before 12 months age are 2-3 times more likely to have disc prolapse during their lifetime than if desexed after 12 months age.

We therefore recommend the age of desexing as follows:

Small Dog Breeds:  from 5-6 months age

Medium Dog Breeds: from 6-7 months age

Large Male Dogs with adult weight more than 20kg:  after 12 months age

Large Female Dogs with adult weight more than 20kg: after 7 months

Dachshunds: more than 12 months age.

What age should my cat be desexed?

Cats are prolific breeders and cat fights are common during breeding season. Developmental joint disease in cats is relatively uncommon.  Desexing prevents unwanted litters and cat fights.

Female kittens reaching 4-6 months age in spring and summer are likely to cycle early and may be pregnant at 5 months age. They can continue to cycle (or ‘call’) for many weeks if they do not become pregnant. Female cats can be desexed while in season.

We recommend desexing female cats from 4 months age during Spring and Summer and 5-6 months age during Autumn, Winter. Male cats should be desexed at 5-6 months age.

Keep your undesexed kittens inside especially in spring/summer – girls fall pregnant, boys get caught up in fights!

I’ve heard otherwise…

  • Some pet owners believe that an inside dog or cat doesn’t require desexing.
    • We commonly encounter unexpected litters from unplanned matings.
  • Some owners are worried that desexing will change their pet’s personality.
    • It won’t. The pet will be the same animal, just a bit calmer.
  • Some pet owners are concerned that their pet will gain weight after desexing.
    • Animals that are desexed have lower calorie requirements than undesexed animals but weight can be managed by controlling the quantity and quality of food offered, and ensuring adequate exercise.

What about older dogs, is it too late?

It’s rarely too late to have your animal desexed.  Modern anaesthetics are safe for most older animals and behaviour and health benefits will be gained with desexing.

What do I do if my dog comes in heat before desexing?

Most female dogs come into heat after 6 months age and cycle once or twice yearly. A dog heat cycle takes about 3 weeks, with bloody discharge during that time.  The bloody discharge will be messy.  Dog nappies can help control the mess. Male dogs will be attracted to your house while your dog in heat and are more likely to jump the fence into your yard.  Some female dogs are more likely to roam while on heat.  Dogs can mate through a chain wire or pool fence with the male and female dogs on opposite sides.

If your female dog comes into heat before desexing and there is no possibility of the dog having mated, desexing is usually done about 2 months after the dog has finished being on heat.  If the dog has been mated, and you do not wish to have a litter, desexing is done about 3 weeks after the heat.

What happens when an animal is desexed?

Desexing is done as a surgery day procedure. In males, the testicles are removed, in females the uterus and ovaries are removed.   Animals recover from the surgery quickly. With good pain relief in the 3-4 days after surgery, owners often comment that their pet didn’t really notice that they’d had an operation.

What about medical desexing?

A non-surgical implant is available that temporarily and reversibly prevents reproduction for male dogs.
It gives them the health and behaviour benefits of desexing for up to 18 months, without having to have ‘the snip’.
It’s a good option for old male dogs if desexing has been advised for health reasons, and for younger ones when you only want a temporary stop on fertility.