As sick as a dog
Meaning
To be extremely ill, often involving symptoms of nausea and vomiting.
Origin
The phrase vividly connects human illness with the common, often messy, sight of a dog vomiting. Dogs, particularly those that scavenge or eat rapidly, are frequently observed being sick, making it a familiar and easily understood metaphor for intense physical discomfort and nausea in humans. This powerful image evokes a strong sense of a creature utterly miserable and unwell, often to the point of throwing up. The phrase gained widespread use by the late 18th century, cementing the dog's unfortunate reputation as a symbol of extreme sickness.
Examples
- After eating the questionable seafood, John felt as sick as a dog all night.
- I had to leave the party early because I suddenly started feeling as sick as a dog.