A children's book written by Renè Guillot. Translated in Italian as "Griska e l'orso". Published originally by Hachette in 1963, it tells the story of a young boy living somewhere in the tundra (I would venture in the Soviet Union). He grows together with a foundling bear cub. Griska has to face a very hard moment when the tribesmen decide that the time to sacrifice the bear has arrived.
This is one of my oldest memories of books. And I remembered it only because Gritchka mentioned it.