The faithful Ruslan of the title, and the hero of this novel, is a dog: a loyal, adoring, innocent caucasian sheepdog who is also a vicious prison guard dog. Until, that is, the gulag in which he is employed is shut down. Having dodged death by the hand of his master, Ruslan is freed into a world that doesn't respect the rules of his previous regime; but these rules are all Ruslan has and he grimly hangs on to them like some terrible, toxic bone.

Taught not to accept food from anyone but his master, Ruslan survives on dedication to old duties, mouthfuls of snow and the odd hunted mouse. Other colleagues in the service might slink off to be fed and taken in by civilian owners, but Ruslan has more moral fibre.

When he finally understands his master has betrayed him, the proud, eager dog forms an allegiance with "the Shabby Man", an ex-detainee who may think he is Ruslan's new owner, but who would be mistaken: Ruslan is guarding him until the Shabby Man returns to the labour camp. He "carries devotion to the point of fanaticism", observes the head of Ruslan's pack; a view affirmed by Ruslan's tragic misinterpretation of events at the novel's close.

This slender dissident novel, published in 1979, is Vladimov's accepted masterpiece, an expanded version of his story "The Dogs" from the mid-1960s. It is easy to see why neither version has ever been officially published in Russia. The mindless cruelty of Stalin's enforced labour system – through which approximately 14 million people passed between 1929 and 1953 – is clearly communicated.

The allegory of the unquestioning subordinate – the myrmidon – and their part in such atrocities may not be all that subtle but the dark, ironic humour is precise as a scalpel; and the climactic scene emphatically not for dog-lovers.