KEY POINTS:
New Zealand men's sympathy for their pets' packages is an "ecological disaster waiting to happen", Unitec research has revealed.
It has shown that many Kiwi men do not have their pets neutered because they are concerned what the operation will do to their beloved animal's sexuality or masculinity.
Evidence from the SPCA-funded study showed just 80 per cent of men sterilised their cats or dogs, compared to more than 90 per cent of women.
Only 66 per cent of men thought all cats and dogs should be desexed unless for breeding, compared to 88 per cent of women.
Almost a quarter of men surveyed believed cats and dogs had "the right to remain whole".
The study's principal academic, Mark Farnworth, who conducted the research with undergraduate student Stacey McKay, said the research highlighted an alarming danger to New Zealand's ecology.
New Zealand only had two native species of mammal, both bats, which were constantly preyed upon by populations of dogs and cats "out there breeding on their own".
The bats were not equipped to deal with the threat and their populations were struggling as a result.
"It's really an ecological disaster waiting to happen."
Men need to get over their fear of stripping their pets of their masculinity, and stop believing that pets should be allowed to have one litter before being desexed.
That was "completely untrue", and only served to increase the population of dogs and cats, while also increasing the animals' chances of developing reproductive cancers, he said.
The SPCA received about 40,000 cats in the last year, of which about half had to be put down as homes could not be found.
About 6000 dogs were also put down for the same reason each year, he said.
Desexing pets actually made life easier for most pet owners. Dogs especially were easier to control after being desexed.
"Men need to get over themselves and realise having a dog with no testosterone is neither being cruel to their dogs, or diminishing their masculinity."
