***Correction*** I orignially wrote that Study of a Pomeranian was by Leonardo da Vinci, because it's sold all ove the Internet that way. But a little research revealed it is actually attributed to Francesco Melzi. But, scroll down and you will see The Head of a Dog that was made by Leonardo da Vinci in 1497. I think it looks a little like Darby. I hope it was a sweet companion and not a specimen on his dissecting table.
I've lived in Florence. I've studied a tremendous amount of Renaissance art and history. I had no idea Leonardo da Vinci was a dog artist.
If you don't have anything to do today, visit the Windsor Royal Library's online collection of 825 Leonardo da Vinci sketches. Mind-blowing.
Have a great weekend.