Interpretation
Louis H. Leiter saw in the tale a cogent argument for existentialism:
"A Country Doctor" comments on man, who, buffeted by the scheme of things, is unable to transcend the part assigned him by the absurdity of that existence. Because he does not lack conscious knowledge of his condition, but refuses to act in the face of his portentous freedom, the doctor, an archetype of the anti-existential hero, deserves his fate. Lacking the human stuff necessary to create and structure situations, he permits himself to be manipulated by the groom, the family, and the horses; but he becomes, by submitting, a tool within the situations they create. Never, consciously, does he attempt through an overt act, until too late, to establish his own essence, to rise above any manipulative value he possesses for others. As doctor he is a thing, an object, a tool; as man he is nothing.
Read more about this topic: A Country Doctor (short Story)