What does " A Horse on you" mean? Where does the "Horse" come from??

While playing many Bar dice games, such as: Poker, or Boss dice, ship, captian and crew. Just about any dice game that you play two out of three. What does " A Horse on you" mean?

referring namely to you, et al.

A stronger way of saying the phrase, "fuck you and the horse you rode in on".

term used to tell someone to fuck off and get off there pedestal

a term used when pissed at a boss or an authority figure when they feel they are better than you

From one of the first popular jokes using profanity:
Old West Bar, men playing poker. Lone Ranger comes in. "You're all under arrest for gambling!"
The poker players say, "Fuck you!"
"But I'm the Lone Ranger. These are my silver bullets, and that's my horse Silver!"
"Well then fuck you and the horse you rode in on!"

1) a response to an expceptionally stupid remark
2) an elevated form of fuck you, usually used when someone continues to ride you in a conversation.