This section of the book is from the "Stories of Animal Sagacity" book, by William Henry Giles Kingston.
I must give you another anecdote somewhat similar to the last.
A little terrier, and another dog, equally faithful and sagacious, had attached themselves to their master’s horse, which they always accompanied when it went out. If the master rode out on it to dinner, the two dogs used to remain contentedly in the stable with their friend, till it was required to carry its master home.
One night the gentleman had ordered his horse to be brought, but waited in vain for its appearance. At length the groom was summoned, when he declared that he dared not take the horse out of the stable, as one of the dogs was on its back, and the other by its side, threatening to attack every person who came up to the animal. The owner, observing that the groom was a stranger, suspected at once that the dogs would not trust him, and had himself to go round to the stable, when the faithful animals at once delivered their charge up to him.