Alvin, I don't hate cats, but then again I only have one cat that is mine rather than a whole bunch of feral cats ransacking my orchids. I don't blame you for hating them. I would too!
I co-exist with my little hell-cat by working with her. I observe her habits and adjust my growing areas accordingly. If I have something that I really don't want her messing with I move it to another room and keep the door closed. Most importantly, I grow a pot of wheat grass for her to chew on instead of my plants.
Unfortunately, these methods wouldn't work for feral cats outdoors. Since you are in mourning over your last dog, I second Al's suggestion. Can you make an enclosure for your orchids? Kind of like my closed room, an enclosure would be the surest way of keeping the cats out of the chids.