I have had a lot of cats in my long life - and I do believe without a doubt the best natured are the neutered males.
My last neutered male would be a little fearful and somewhat aggressive toward a new little pet when I first got it - but I'd sit on the sofa beside my cat with the new pet in my lap and totally not allow him to be mean. And, within days and a little time together - he would become a totally inseparable friend to every new pet I brought home.
I have also read (and I totally believe it) that a neutered male cat often makes the best surrogate mother to any young animal (kitten or puppy).
THIS IS IMPORTANT -- it certainly helps that any new pet brought into your house is very young - just a baby - if you want your cat to take a real liking to it.
So - I suppose having a Yorkie and wanting it to get along with a cat - would mean that your chances of success are much more - if he meets a little kitten...and not an older cat.
Good luck!
Carol Jean |