Once a few years ago I stopped and met a young Great Dane and his human companion walking along the canal. I'd seen them before and noticed this beautiful dog. I asked if I could take some pictures and the man said yes. The dog was a little shy of me at first. I got some great pictures of him running and playing with me. He wouldn't let me pet him though. When I went to leave and got back on my bike the dog decided to follow and gave chase which was fun until he caught up to me and put his mouth around my arm. He was careful not to bite down, he was just playing. But I realized that dog could easily take me off my bike and when he released me I sped up enough that he gave up and turned back to his owner. I've seen them out many times after that. I haven't seen the dog unleashed since then though.