在英語口語中，固定搭配“as sick as a dog” 通常用來形容一個人因為吃壞了肚子而在一段時間內“身體很不舒服，病得很嚴重”。在描述吃壞肚子的上下文中，“as sick as a dog” 也可以指一個人“嘔吐得很厲害”。它可以和動詞“be” 或“feel” 搭配使用，即“to be as sick as a dog” 和“to feel as sick as a dog”。
I’m going to have to get off the train as I feel as sick as a dog.
Doctor, I was as sick as a dog after eating a pineapple. I vomited a lot.
He couldn’t come to work yesterday because he was as sick as a dog. He ate too much the night before and felt really ill.