The Night Horseman by Max Brand

The chain which fastened Black Bart had been passed around the trunk of a tree that stood behind the ranch house, and there the great dog lay tethered. Doctor Byrne had told Whistling Dan, with some degree of horror, that the open air was in the highest degree dangerous to wounds, but Whistling Dan had returned no answer. So Black Bart lay all day in the soft sand, easing himself from time to time into a new position, and his thoughtful eyes seemed to be concentrated on the desire to grow well. Beside him was the chair in which Dan Barry sat for many an hour of the day and even the night.

Kate Cumberland watched the animal from the shadow of the house; his eyes were closed, and the long, powerful head lay inert on the sand, yet she knew that the wolf-dog was perfectly aware of her presence. Day after day since he lay there, she had attempted to approach Black Bart, and day after day he had allowed her to come within reaching distance of him, only to drive her back at the last moment by a sudden display of the murderous, long fangs; or by one of those snarls which came out of the black depths of his heart. Now, a dog snarls from not far down in its throat, but the noise of an angered wild beast rolls up out of its very entrails -- a passion of hate and defiance. And when she heard that sound, or when she saw the still more terrible silent rage of the beast, Kate Cumberland's spirit failed, and she would shrink back again to a safe distance.