I figured out the answer to the question by myself, so here it is:
Answer:
In this particular scene from the above excerpt taken from George Orwell's "Animal Farm," the narrator explains that Napoleon had now felt he had become so powerful that he did not need to appear in front of the other animals as often; when he did arrive, however, he brought his pack of dogs and a black cockerel to protect him and give out a warning to the other animals should anything happen. The reader would be able to discern the meaning of the word "retinue," as it is used in the excerpt above, by their knowledge that Napoleon had raised a pack of dogs to fight for him. In this case, retinue acts as a synonym to "pack".
