When Cesar is walking alone and sees the dog, he says "stupid gato", which means stupid cat, not dog. This could just be because he is high as a kite though.
In the beginning of the film, Mr. Garfield does a demonstration with a bicycle wheel in order to teach 'centripetal' force. The demonstration is actually used to demonstrate 'conservation of angular momentum'.
Trevor Garfield: Like you, I used to think the world was this great place where everybody lived by the same standards I did, then some kid with a nail showed me I was living in his world, a world where chaos rules not order, a world where righteousness is not rewarded. That's Cesar's world, and if you're not willing to play by his rules, then you're gonna have to pay the price.