Via numerous posts, many of us are aware of Fozzer's negative affinity to cats. You must realize, however, if a cat isn't part of your family, it applies the "beware of strangers" to you. Many dogs have immediately welcomed me on a friendly note, especially if it seemed I was in good favor with their owner; cats have befriended me, sometimes unexpectedly, but only after they analyzed my attitude with their owner (not just their owner's attitude toward me).
Anyway, I came across this article in the online Washington Post.
Try teaching your dog to do that on a standard toilet.
Actually, however, manufacturing appropriate-sized pet toilets, particularly for cats and dogs, might result in their ability to actually flush them. From my experience, the whole procedure may be a little more difficult to teach the dog -- but if the dog sees the cat doing it, the dog can follow suit. If you have a dog and no cat, you can strip from the waist down, get on hands and knees and... well, you get the picture but we'd rather not...