Antique Dog Collars.... the collar in the middle (3rd from the bottom, 4th from the top) looks perfect for Zachariah.
THE CLASSIC MASTINO Collar Handmade Leather Dog Collar Made to Order Free Shipping. $129.95, via Etsy.
medieval dog collars http://www.leeds-castle.com/Attractions/The+Dog+Collar+Museum
DOG COLLAR, LURCHER, GREYHOUND, HANDMADE, UNIQUE DESIGN, ENGLISH LEATHER. | eBay
Stuttgart Playing Cards - 2 of Hounds, c.1430
Chaucerian dog - It's About Time: Dog Days of Summer - Over 40 Dogs of the Middle Ages "rescued" from illuminations, tapestries, & even playing cards...
Portrait of a Gentleman with a hunting dog. Date 1569
Medieval Dog Collar (2 of 2)