The Night Horseman by Max Brand

Bandages and antiseptics and constant care, by themselves could not have healed Black Bart so swiftly, but nature took a strong hand. The wound closed with miraculous speed. Three days after he had laid his head on the feet of Kate Cumberland, the wolf-dog was hobbling about on three legs and tugging now and again at the restraining chain; and the day after that the bandages were taken off and Whistling Dan decided that Bart might run loose. It was a brief ceremony, but a vital one. Doctor Byrne went out with Barry to watch the loosing of the dog; from the window of Joe Cumberland's room he and Kate observed what passed. There was little hesitancy in Black Bart. He merely paused to sniff the foot of Randall Byrne, snarl, and then trotted with a limp towards the corrals.

Here, in a small enclosure with rails much higher than the other corrals, stood Satan, and Black Bart made straight for the stallion. He was seen from afar, and the black horse stood waiting, his head thrown high in the air, his ears pricking forward, the tail flaunting, a picture of expectancy. So under the lower rail Bart slunk and stood under the head of Satan, growling terribly. Of this display of anger the stallion took not the slightest notice, but lowered his beautiful head until his velvet nose touched the cold muzzle of Bart. There was something ludicrous about the greeting -- it was such an odd shade close to the human. It was as brief as it was strange, for Black Bart at once whirled and trotted away towards the barns.