sick as an ANIMAL
adjective physically sick, but not necessarily vomiting. The earliest recorded is 'dog' (1705); followed by 'horse' (1765); 'cat' shows up in 1915, and 'sonofabitch' in 1953. 'Sick as a parrot' is a jocular variation from 1979. On 20th November 2000, Judith Keppel was the first contestant to win a million pounds on the television quiz
Who Wants To Be A Millionaire; the first question she answered (for £100) was: 'Complete this phrase. As sick as a – Puffin – Penguin – Parrot – Partridge'
UK, 1999