When I take my dog outside to go to the bathroom he sometimes comes back inside eating a leaf. I try to get it from him, but once he snapped at me and sometimes he won't open his mouth. It's not every time he's out just sometimes. Is that healthy, or shouldn't I worry about it?

***Edited By: Cotonbuddy on 2/25/2012 5:08:36 PM***
Reason: fixing things