3#木人仔The alternative is lots of wild cat. Wild cat killing native wild live. Forest ranger resorting to hunt wild cat by guns or even worse by baiting. e.g. dissolving panadol in milk. This would destroy the cat's liver function. The wild cat would die in a very painful death but minimal impact to other wild life. Even if you live in city, wild cat living on garbage... I think it is just cruel. Or euthanasia by your local humane society.
What I am saying the alternative of not desexing your pet is outright "EVIL", "CRUEL", "IRRESPONSIBLE" (take a pick)? there is not much if or but. The only case that you do not desex your pet is if and only if you intend to breed the dog or cat for a period of time. When you finish breeding the pet, you should still desex the pet.
There are other advantage of desexing pet. The life expectancy of the dog and cat improve a lot ~couple years typically, check with your vet. (mainly apply to female).
In modern society, a responsible father/husband would choose to perform vasectomy. The risk of complication for male is much lower than female. Even this is acceptable for human society. Why do you think it is not acceptable for cat/dog?
I am not trying to start a flame war nor behave as a troll. The idea of not de-sexing your pet and responsible pet ownership just don't add up.