In the original "Animal Farm" George Orwell creates an allegory to the socialist revolution in Russia in which the farm animals liberate their farm from its exploitative and corrupt human owner to create a fairer farm where the animals are the owners and benefactors of their own work. However, the pigs (representing the bolsheviks) led by the power-hungry Napoleon (Stalin) quickly subvert the ideals of the revolution and end up becoming the evil they had replaced: cruel rulers walking on two legs rather than four.
In Animal Farm 2 (fictional, don't bother looking on Amazon), the pigs are the sickest and poorer animals of yet another farm called the EU. When bad times fall upon the farm its owners become hungry and decide to call the butcher, the creepy IMF, to slaughter the pigs for their own benefit.
How the story ends, nobody knows. All we know is that it will be bloody.[link]