In chapter V of Thomas Hardy’s Far From the Madding Crowd, farmer Gabriel Oak’s immature sheep dog (referred to as “George’s son” below) driven Oak’s flock over the cliff. Hardy writes:

George’s son had done his work so thoroughly that he was considered too good a workman to live, and was, in fact, taken out and tragically shot at twelve o’clock that same day–another instance of the untoward fate which so often attends dogs and other philosophers who follow out a train of reasoning to its logical conclusion, and attempt perfectly consistent conduct in a world made up so largely of compromise.

As for dogs as philosophers, see Book II of Plato’s Republic.