its useless to talk to those people about cats...unless its to say to them when they say something, oh well thats what happens when you dont have cats!
like if they are lonely, bored, or whatever. find any excuse you can to say that to them, maybe then they will get the hint to not say that to you anymore! lol

or if its about a sick cat, then they say that, then you could say the same to them, well see you should have had cats not kids!
(of course I mean only if the kid is not seriously sick)