Historical clue formulations

• Canine breed named after an English river valley — 2025-07-19
• Black-and-tan purebred — 2008-07-08
• It's black and tan — 2006-09-15
• It's black and tan — 2000-05-19
• Dog used as a wartime dispatch bearer — 1998-12-19
• Yorkshire dog — 1996-08-23