Let’s face it, territory marking with urine, straying & stinky tom cats, bitches dripping blood on the floor, endless litters of kittens without homes, fights between testosterone-crazed dogs: there are many reasons why you might want to neuter your pets.

  • It will probably stop your tom cat from smelling like a tom cat
  • Your female cat will not get pregnant
  • Neither will your dog
  • She will not come into season either, so no more bleeding twice a year
  • She will be much less likely to develop mammary cancer in later life
  • It’ll probably reduce aggressive behaviour between male dogs

But neutering is not an entirely benign procedure, and if carried out too young, there is evidence that it can result in increased fearful behaviour. Certain types of tumours become more common. Some animals need less food but paradoxically are more hungry, so you may need to be particularly careful with their weight. Some aging female dogs become more likely to leak a little urine (but in most cases this can be treated medically).

So What Should You Do?

There is no perfect age, but our current advice on neutering is:

Female dogs: neuter between first and second seasons, so at around 12-15 months of age. We don’t recommend repeated use of hormone treatments to temporarily suppress the signs of a season.

Male dogs: neuter them if their testosterone levels are getting in the way of their (and your) peaceful enjoyment of their lives. If they are perfectly well adapted to life as an entire male, leave them alone. If you are uncertain, there is a temporary chemical neutering with a hormone implant that lasts around 6 months. This will closely mimic what they would be like as a neutered male and can be a useful trial procedure.

Male and female cats: neuter at around 6 months of age

  • If you are thinking of neutering for behavioural reasons, be aware that not all behavioural problems will get better with neutering
  • A vasectomy will make an animal sterile but will not affect their testosterone levels, so will not affect their behaviour