Throughout George Orwell's Animal Farm, the comrades fall prey to a number of logical fallacies. One example of this is during the election between Snowball and Napoleon. Here the animals succumb to the Either-Or fallacy, which is a type of half-truth.
Snowball wanted to build a windmill, so the motto for his faction was: "Vote for Snowball and the three-day week." He argued that building the windmill would mean the animals would not have to work as hard. He believed building the windmill would result in the animals only have to work three days a week, but the motto represented this belief as a truth. Therefore, it is a fallacy.
Likewise, Napoleon's slogan was: "Vote for Napoleon and the full manger." Napoleon believed (or at least claimed to believe) that building the windmill would cause the animals to neglect their work, causing them to not have enough food. The animals who backed him believed that voting for Napoleon would bring "full mangers," but they represented this belief as a truth.
Additionally, both factions engaged in the either-or fallacy. They claimed that either their candidate would win and good things would happen, or the other candidate would win and bad things would happen. They did not acknowledge the possibility of any other options.