Somewhere at the Metropolitan Museum of Art rests a 400-year-old dog collar of forest green. Crafted from silk, leather, and gilt metals, it was once worn by a dog who hunted for the Dukes of Saxony. I'd love you to see it - it's here.
Quick addendum! Over at the Philadelphia Museum of Art, there is a silver dog collar from the 19th century. Though the maker's mark upon it is French, the other side of the collar bears in plain English: "John Potter, Green Lane Station." A fancy souvenir for Fido? This museum also owns a simple engraved brass collar made in Philadelphia in 1786.