sick as a cat

sick as a cat (not comparable)

1. (simile) Very ill.
   • 1886 October – 1887 January, H[enry] Rider Haggard, She: A History of Adventure, London: Longmans, Green, and Co., published 1887, →OCLC:

     `My head is splitting, my body is trembling, and I am as sick as a cat.'

• sick as a dog
• sick as a parrot