My first time on Quilting Board, but just had to reply. We have a 7 year old Shih Tzu, (Queen of the house). Last Winter on the worst possable snow day, she suddenly could not go potty. It was heart wrenching to see her try. The Vet (we live in a pretty small town) met us and after a few tests told us she had Bladder Stones, and needed surgery right away. Her little Bladder was completly filled with stones, and she could no longer uriniate. She recovered, and we keep an eye on her with regular urine tests. Some of the stones were as big as a lima bean! We were told Shih Tzu's are prone to this.