What are the potential side-effects of spaying or neutering a cat?
We have three cats (one male, two female), the male and the younger female are sibblings.
The younger female was not spayed until half a year ago (all the others were spayed/neutered when we got them).
The only thing I noticed is that she got a lot more food-centric and thus gained a few half-kilos (which is a good thing in her case, as she was quite thin before).
She didn't change at all in any other aspect (not less energy or more agression, nothing), so it was definitely a good change.