It's a useless action. (A dead horse won't pull your wagon no matter how much you beat him.)
"When the horse is dead, get off" means you should not waste time on things that are not worth it. If the horse is dead, you can't ride it any more.
Hay
Horse dander are dead skin cells that fall from the exterior of the horse. Dander is most noticeable during grooming.
A long time ago, the horses that died in a war were buried at the beach. But the next day, people found the horses dug up. And everytime after that, the horses kept coming up, so they named the beach Dead Horse Beach.
The Dead Horse Trail or Dead Horse Pass was a nickname for White Pass during the Klondike Gold Rush. It was named this because so many pack horses died on the attempt to cross over the pass. Horses were dead along side the trail and sometimes the dead horses were trampled right into the dirt and mud as thousands of people and horses walked over their remains on the trail. Some estimates say over 30,000 horses dies there.
Beating a Dead Horse to Death... Again was created on 2008-10-28.
- My efforts are futile - Pissing in the wind (Australian slang) etc. bark at the moon catch at shadows bite a file beat the air in vain plough the air etc.
The actual quote is "stop beating a dead horse" stop wasteing time on a pointless activity.
This is a horse term. Flogging is beating with a whip. It does no good to beat a horse that is dead, because it will never get back up and work for you.
It means that you should stop talking about the subject because it's useless and already been talked about enough. (A dead horse won't do anything for you, no matter how many times you beat it.)
Raising the Bar - 2008 Beating a Dead Horse 2-12 was released on: USA: 24 August 2009 Finland: 19 February 2012 Japan: 8 September 2012
Usually "flogging a dead horse" imagine you are beating the horse trying to get it to move even though it is dead. It means that you are trying to do something that cannot be done.
Going around in circles, beating a dead horse. An expression regarding a repetitive useless behavior.
Someone would be called clinically dead when their heart stops beating.
"A bit of dead horse" is Australian slang for tomato sauce.
Beating Dead Horses was created on 2011-05-10.
It stinks!