How does Boxer escape from being attacked by Napoleon's dogs?
The episode you are talking about happens in Chapter 7.
Boxer had been saying that he has a hard time believing that Snowball was always a traitor. When it is pointed out that Napoleon says so, Boxer does his usual "Napoleon is always right" and that seems to be the end of it.
But at the next meeting Napoleon sics the dogs on some pigs and even on Boxer. Boxer escapes because he is so strong. He kicks a dog and then pins it to the ground. The other dogs run away. Boxer could have killed the dog, but he obeys Napoleon and lets it go.
In the book "Animal Farm" Boxer continues to work harder and harder. He never complains and when the others try to tell him not to push it so hard he just repeats the commandments. He constantly repeats "I will work Harder." This seems to suffice everyone around him, especially Napoleon and the pigs. His other slogan is that "Napoleon is always right."
Boxer's dedication to the cause is a shame because he gives so much of himself and will receive nothing in return. Even when the animals are always cold and hungry, Boxer continues to say his slogans and continues to work. Even when everything gets bad he takes the blame and puts it on his-self and the others rather than having a true understanding of where the problems were developing.
Boxer's hooves just hit one of the dog's head, and then the rest of the dogs are scared of Boxer