Answer: Orwell's tone when describing the animals' reaction to Squealer ("The importance of keeping the pigs in good health was all too obvious") is markedly ironic and again signals to the reader that the pigs are slowly changing into a new form of their old oppressors.
Situation irony occurs in Animal Farm when Napolean gets drunk, “By the evening, however, Napoleon appeared to be somewhat better, and the following morning Squealer was able to tell them that he was well on the way to recovery.
