farmers first try to cheat the animals, and then start working with the pigs. One farmer jokes:

"If you have your lower animals to contend with," he said, "we have our lower classes!" This bon mot set the table in a roar...
(Orwell, Animal Farm, msxnet.org)

This shows how uncaring the humans (capitalists) actually are, although the animals are certainly worse off under Napoleon than they were under Jones.

From the onset, George Orwell criticizes all form of political tyranny. He saw first-hand how Communism, an extreme form of socialism develops in much the same away as any regime. As politics is such a sensitive subject and difficult to interpret, he uses farm animals in the development of this story about power, abuse of power and importantly, idealism. He drew analogies between his characters and the major proponents of the Russian Revolution in an effort to warn people of the dangers of any extremism.

Animal Farm is a criticism of Communism but Orwell does not suggest that a western- style government is any better. The animals represent the Russian communists and the farmers represent noncommunist leaders. Mr. Jones proves an irresponsible and neglectful farm owner, and neither Mr. Pilkington nor Mr. Frederick hesitates to squash any animal uprisings that threaten his own supremacy.

Being equal has never meant being the same but due to the fact that inequality is pre-existing because there will always be someone who is cleverer, more good-looking, a better speaker, dresser and so on equality remains an ideal and as such is open to abuse.  

The ignorance of some of the animals allows the pigs to slowly exert their superiority. Communism is based on the belief that an autocracy is okay until the system is established, whereafter the people will assume control themselves. Clearly this did not work for the animals.

At the onset, when Jones is overthrown, the Commandments are based on what not to do and who not to be like as the animals have no base from which to create their own ideal. They can only supposedly improve on what existed before. The pigs are able to manipulate the animals due to the fear of returning to life under the humans.

Orwell criticizes this abuse as it is so subtle at first.

Somehow it seemed as though the farm had grown richer without making the animals themselves any richer.

Unfortunately, being a part of the whole is never enough and the elements - the pigs- ease the animals from one desperate situation into another. Orwell makes the distinction between what the animals think they are fighting for and what they are actually fighting for. As the novel progresses, the ideals are watered down to suit the pigs: 

No animal shall sleep in a bed with sheets,

and the sixth commandment says

No animal shall kill another animal without cause.

 This culminates in the ultimate betrayal:

All animals are created equal, but some animals are more equal than others. 

Read the 'recommended question' which will also expand your understanding of Orwell's intentions in writing Animal farm.