The book starts off with the revolt against the human. Then the taste of freedom. Soon new rules are made for welfare of the animal. Pigs are intelligent when compared to other animals. Taking this into advantage pigs starts being at a better position. Soon all the good things are allowed for the pigs. The prior rules or commandments are changed according to their own comfort.
Sadly this can be related to actual communal situation. Once having power they are ready to do every sort of thing for their own benefit. Eliminate of anyone stands against them. Even many powerful people do follow this. People need to be educated and understand how this will affect us. Can be related to communism.
Present day example, shabarimala problem created by the cpim gov to make people fight over religion. It just relatable to this book's situation. Powerful people have control over everything whereas others are revolting but not so fruitful.
All animals are equal, but some animals are more equal than others.