This may not be the same problem you're having but my snap peas were doing the same thing and I was confused and worried about them - then one day I managed to catch my dog "marking" them. He's a pretty good dog, so I only had to scold him once - no more dying peas!

Hey Pluto, that's interesting, and I will watch my dog. The thing is though that my dog has an obsession with urinating in the ivy bed far from the garden. He also knows the garden is off limits to him. I just can't imagine that being the case here...? I will watch him though, and thanks for the input.

Need pictures please