Why does Napoleon think he's dying the morning after he drinks the whiskey in Animal Farm?

The
Fifth Commandment originally states that "No animal shall drink alcohol," but is
broken byin . After the windmill is destroyed andannounces that the animals are once again
victors, the pigs come across a case of whiskey in the cellar of the farmhouse. The other
animals hear the pigs partying all night long and even spot Napoleon race around the farmhouse
wearing Mr. Jones's old bowler hat. However, the next morning there is a solemnon the farm
because the pigs believe that Comrade Napoleon is dying. There are even rumors spread throughout
the farm thathad poisoned the whiskey. At eleven o'clock, Napoleon even decrees that the
drinking of alcohol is punishable by death. However, Napoleon begins feeling better the same
evening and is completely fine the next day. Essentially, Napoleon was suffering
from a hangover, which made him feel nauseous, tired, and sensitive to light. By
the end of the chapter, the pigs begin researching how to make alcohol and the Fifth Commandment
is rewritten, "No animal shall drink alcohol to excess."