My dad's allergic to certain cats, but there's no rhyme or reason to it... my auntie's two cats set him sneezing straight away, yet our own cat (turned up on the doorstep, wouldn't leave
) doesn't bother him at all.
Speaking of our own cat, Sid - for some reason or other, he seems to favour pink
yarn... and if he gets hold of it, he actually starts eating it until he chokes on it, so I have to be soooo careful if he's about. Poor creature.