Just a little tidbit on this:

Every dog owner I know is very responsible, cleaning up after their dogs
always. The large majority of dog owners are responsible about this;
they know if they aren't their dogs will be kicked out of all parks, not
just limited to leashes.

That said, you can keep the nasty few from pooping up our parks by making
a scene if you see someone leaving a fresh pile. Just ask them nicely,

'Are you going to clean up after your dog?'

____________________________
Mike Smith
Univ. of Washington, Seattle
whimbrel at u.washington.edu
http://salmo.cqs.washington.edu/~wagap/mike.html