Now that I've converted my own cats to indoor-only animals
due to the loss of Canopus in April 2006 to being hit by a car--my first-ever loss of an indoor/outdoor cat to a car--my garden is defenseless.
Or, it WAS defenseless until a neighbor cat decided to nap in my raised beds. I couldn't tell whether the cat was owned or stray for a very long time. I knew it wasn't feral, because it was friendly to me, responding to the "Here, kitty, kitty, kitty" universal call.
But having this large gray cat clearly present in the veggie beds, on the porch, and elsewhere around the place has sharply reduced the number of squirrels and mice messing things up! As for his potty habits (I'm assuming Large Gray is a boy; I haven't examined "him"), Large Gray is very discreet. I've only found two unwelcome deposits in all these months. I lifted them out of the raised bed where I found them (using a trowel!) and put them into plastic bags, just like I do with dog waste.
But that's me. I LIKE cats. I LIKE dogs.
For people who don't want cats in their gardens, I have a couple of NON-VIOLENT recommendations:
--chicken wire laid down around your plants or simply in the aisles of your row garden.
Sunset Zone 17, USDA Zone 9