My 8 week old puppy eats everything of interest when she's outside on a leash. I mean everything. Leaves, grass, weeds, mulch, stones from the driveway, etc. What to do? She's in a harness and about the only way to prevent her from eating all this stuff is to hold the leash tightly so she can't put her head down all the way. Would a muzzle work? Is there some sort of behavior deterrent that can be used?
I had hoped to build a dog run but at this point she's not able to be outside and unsupervised.

Thanks!