"Cowboy and the horse" joke

(Read in a Turkish newspaper:)
Old west... A bar... All of a sudden, the door opens with a kick, and
a cowboy in black enters... Black hat, black foulard, black shirt,
black trousers, black boots, black gloves, black belt, and a black
pair of guns...
Everyone looks at him with fearful eyes. He approaches the barman, and
asks:
"Do you have a bucket?"
Barman runs inside, finds a wooden bucket, comes back. The cowboy in
black looks to the bucket, and orders:
"Now, bring me three bottles of whiskey."
Seconds later:
"Pour them into the bucket."
And, then:
"And now, bring this to my horse outside."
The frightened and surprised barman does what the cowboy in black
tells.
He finds a horse, black as night, tied in front of the bar, completely
in black harness. It drinks all the whiskey at once.
Then the barman returns back inside the bar. The cowboy very carefully
looks into the bucket, sees that nothing is left, and asks:
"What do I owe for this?"
Barman, while calculating the price, asks:
"Won't you drink anything?"
The cowboy in black replies:
"No. I don't drink and drive."