I have 2 un-neutered male siamese kittens. They are coming up 10 months old and we recently also got a puppy. They all seem to get on well and in fact one of the siamese seems to be the leader of the pack. However all of a sudden the cats seem to be peeing over the house instead of the litter tray. Anyone know why this is and what i could do to stop it? I would assume its to do with the puppy?