In Animal Farm the dogs of the farm came to represent Stalin's KGB or secret police. There job was to keep order through any means necessary. This usually came down to the imprisonment, interrogation of otherwise innocent people to set an example to the rest of the population. This secret police force would seize people in the middle of the night, take them to a hidden place where they would proceed to beat them until they admitted to a crime the may have not committed. By setting this type of example and ensuing fear into the entire population, Stalin was able to control the entire mass of Russia with relative ease.
The book Animal Farm by George Orwell is an iconic book about the Russian revolution.