I had one and my single Choc. Lab overwhelmed it in about 1 month.
I use this to clean up after our dog, and just toss the bag in the trash, it takes me about 4 minutes each evening to scoop up the presents. Then every 3 days or so I toss the bag in the trash the night before trash day.
http://www.petsmart.com/product/index.jsp?productId=2755080
