I like paintball guns.  Causes pain and leaves a mark.

I had a dog that would dig under my fence.  So I pegged it a few times.  The neighbor came over throwing a fit about his paint covered dog.  I told him to show me any paint in his yard and I would show him the splatters in mine so we could determine where the dog was shot.

End of story. 

sorry ...but to me that's so, so funny.

I lived in a house once, where that exact thing would happen all the time ... Dogs could 'smell' that other dogs had 'been' there, and every other house in the street was avoided but mine ...bloody puppy land-mines!

So, whilst it's funny ...I feel your anger, pjdark

"dog exhaust"
My neighbor made a wooden tombstone, old western-style, put it in a prominent place in his front yard...
...seems to help some:

"HERE HE LIES,
ALL COLD AND HARD,
THE LAST DAMN DOG
TO POOP IN MY YARD!"