Here's the other version:

SHETLAND PONY BLUES
Son House (recorded 1941)

Why don't you catch my shetland, and saddle up my black mare.
Why don't you catch my shetland, saddle up my black mare.
You know I'm'a find my baby, Lord in, in the world somewhere.

Well, he's a stallion horse, and he don't deny his name,
He's a stallion pony, he don't, deny his name.
You know the way he can travel boy's a low down, oh dirty shame.

Uhm, looky here horse, come on, and let's us go,
Ohh, eee, pony, come on up and let's us go.
Let's we saddle on down on the Gulf of Mexico.

You know, he's a travelin' horse, and he don't deny his name,
He's a travelin' pony, 'n' he don't deny his name.
Oooh, the way he can get out is a low down, oh dirty shame.

You know, I took him by the reins, and I led him around and around.
I took him, by the reins, I led, him round and round.
You know, he ain't the best in the world, but he's the best stud in this town.

Why don't you come up here horse, come on and let's us go,
I said, get up now horse, come on now, now let's us go.
Let's we saddle on down on the Gulf of Mexico.

Ummm, he's got four stocking feet, and great long, oh curly mane,
He's got, four stocking feet, great long, oh curly mane,
He got a high commotion like a I.C., oh passenger train.

By the way, Patton made another version also, called "Stone Pony Blues." It starts out something like

I got me a stone pony, I don't ride Shetland no more(2x)
You can find my stone pony hooked to my rider's door.

One more thing - these pony blues songs show a connection between the blues and the British Isles ballad tradition - variations of the verse "fetch my pony/saddle up my mare" being found in many ballads.