sick as a dog
Meaning
To be extremely ill, often experiencing intense nausea, vomiting, or a general feeling of profound misery.
Origin
The phrase draws its vivid imagery from the undeniable and often pitiable sight of a dog when it's unwell. Before canines became the pampered pets many are today, they were often working animals or even scavengers, and their illnesses—particularly those involving stomach upsets and vomiting—were commonly observed. The comparison isn't intended to be derogatory towards dogs, but rather to powerfully convey a state of profound sickness that is visually evident, making the suffering palpable and impossible to ignore.
Examples
- After eating that dodgy street food, I was sick as a dog all night.
- The flu hit her hard, and she's been sick as a dog in bed for two days.