When I don't do this, or keep it packed densely with plants, my raised beds ARE cat boxes. I had to rename the first bed that I amended "The Cat Box".
When I clear a bed for planting, I HAVE to cover it with chicken wire until the plants are largish, or cats or squirrels make hug craters. Once the seedlings are up, I bend the chicken wire or wire fencing to give it some height, so seedlings don't grow through it.
Himalayan blackberry vines, if old enough and thorny enough, work when I have enough of them to lay them out thickly.
Shredded Thai chili peppers might have worked a little bit, but not after the first light rain.
I tried this: forget about it!
This might have worked by itself, if I had sealed the ends, But covering the wire fencing and both ends with heavy plastic DID work. (Or maybe the fact that these were small pots sitting on heavy cardboard was the deterrent.)