With his perennial appeal to readers, the dog has been an author's best friend at least since the days of Homer and Aesop. The two latest instances of that appeal take familiar forms: Ruslan in Vladimov's novel is an Aesopic sort of dog, interesting primarily for what his story tells us about human life, while Yokon in "The North Runner" ha sHomeric qualities. He will remind readers not only of the loyal Argos in "The Odyssey," but sometimes of the rashly heroic Achilles.

In his introduction to "Faithful Ruslan," Richard Adams, author of "The Plague Dogs," and "Watership Down," says that this novel "is among the greatest animal stories ever written."

The reason for this greatness is the careful balance Vladimov maintains between canine and humanoid qualities in the chief character. Not for a moment does the dissident Russian author let readers forget that his hero has four legs and a nose and ears keen beyond human senses. But Ruslan is also a good Soviet citizen, part of a canine microcosm of Soviet society. This is his pride and his downfall and the element that makes his story memorable.

Ruslan is a guard dog at a "corrective-labor camp" in Siberia-ideal employment for one who loves rules and order above all things, as he does by training and by natural inclination. But he has been born into troubled times. The story opens in the aftermath of Nikita Khrushchev's denunciation of Stalin at the 20th Congress of the Soviet Communist Party; the prisoners have been released, the barbed-wire fences are being bulldozed out of existence, and the prison camp will be transformed into a factory. A guard lets the dogs run free rather than execute them as he should, and Ruslan wanders into a nearby village in a state of deep culture-shock.

"This isn't the camp, you know, where you got your rations and that was that" he is told by Djulbars, who was the senior dog under the old system. "Here, if you don't wag your tail a bit, you don't eat." Other dogs manage to adapt to the new reality, but Ruslan is a dogged Stalinist, fiercely incorruptible and able to think only within the old framework. He finally works out a precarious solution when he meets a former prisoner who is living in the village and moves in with him-"patrolling" him on "independent assignment" until order can be restored.

"Faithful Ruslan" reaches a horrible climax when a trainload of factory workers arrives and starts marching out to the former campsite, confirming Ruslan's feeling that "it was still a camp and not something else." Ruslan begins to partol the line, and other former guard dogs rush to join him-and when the factory workers refuse to behave by prison rules, the dogs attack.

It is not the first-nor the worst-horror scene in the book. Earlier, Ruslan recalls the murder of an informant, the search for his murderer and the execution-scenes made more harrowing in many ways because they are seen through the eyes of a dog.

But worst of all is the memory of a day when the temperature fell below minus-40 centigrade. At that temperature, prisoners are legally excused from working outdoors, but when the men in one of the barracks invoked this privilege, the camp commandant has a fire hose turned on them. This punishment is so brutal that the dogs revolt and attack the hose-a futile gesture. The next day a cart goes around picking up the prisoners' frozen corpes like "large, white, freshly sawed logs."

Spectacular horrors, however, are not what "Faithful Ruslan" is really about. Its true subject is horror as a matter of grinding routine, the conditioning of responses and limiting of vision, the stunting of souls that a totalitarian system imposes until even a dog can perceive that the factory, without barbed wire, is "still a camp and not something else."

"The North Runner" is less complicated and will appeal strongly to a somewhat different readership. Yukon is a real dog, half wolf, half Alaskan malamute, with whom the naturalist author lived for five years in the north woods of Canada. Whn Lawrence bought him from an owner who had abused him, Yukon was "a creature more wolf than dog who had learned early to hate man," and the best part of the book is the beginning account of how the author won the confidence and allegiance of this wild beast.

A series of adventures follows, some precipitated by Yukon's unfortunate habit of picking fights wiht bears, and others by Lawrence's human inadequacies-such as the chilling account of the time he was lost in a bizzard and saved only by Yukon's superior sense of direction . The author sums up his feelings on the subject with the remark that "adventure is something nasty happening to someone else," but that does not make the material less readable. (KEY OFF)(KEYWORD)t the end, both of the principal characters succumb to romance; Lawrence becomes engaged and has to get rid of Yukon, who is totally unsuited to city life. Fortunately, on thier last excursion in the great woods, Yukon meets a female wolf and they go off together, coverting the book into a Canadian equivlent of "Born Free."