
He sounds a nasty person, but then, not everybody likes animals, especially not in their garden. When I was gardening today I found dog poo on my front lawn - now my dogs don't go out the front because it isn't secure, so it was somebody else's dog loose that did it.
And I dug up some cat poo when I was weeding - I don't have a cat, so again, that's from someone else's animal. I wouldn't throw stones at them, but I have a powerful water-pistol to give trespassing cats a good fright and discourage them. The best thing you can do is make sure your dog is secure on your property.
:)