We have an old water pipe that sticks out of the ground behind one of our storage sheds. It's only about one to one and a half feet tall, but it's dark in color and really blends into the landscape. A few months ago, Holly was running after one of our other dogs (I forget which one) and ran into the pipe face first! I was shaking with fear as I ran toward her to check her out, but she wasn't even bleeding. She shook it off and kept on going. I was amazed that she didn't break something in her face, but there wasn't even any swelling. She just had a tiny scratch on her muzzle. I guess it's just evidence of how hardheaded she really is!