I don't want cat shit in my garden!

The cats have been entering my dog yard where my tiny little garden is. And using the garden as a "litter box", damn it! The dog yard has electric fence on the outside for the horses, where it borders the horse pasture, but the gate by the barn was not electrified and the fence along the front yard side was not, either. They can enter both those places by climbing the gate of a post. I don't want them in the yard also because we have four bird houses out there. So, I made "Fort Knox" and the WHOLE yard is lined with electric wire now at the top of the fence. :D So far, so good.