Meaning:
“细” means “thin” (as in a “thin thread”), and “狗” literally means “dog.” Originally referring to a dog species recognized for its extremely slim body native to East China’s Shandong Province, this term has been used by Chinese netizens to refer to very thin men. The term is a bit derogatory, implying that the person described is physically weak and perhaps incompetent in fulfilling certain jobs. No one would like to use it on themselves, unlike the other phrases containing the character “dog” (eg., “single dogs”).
Example:
A: 你每周健身几天？
Nǐ měizhōu jiànshēn jǐtiān？
How often do you go to the gym?
B: 最少五天。
Zuìshǎo wǔtiān。
At least five days a week.
A: 坚持得真好！
Jiānchí de zhēnhǎo！
You are so persistent!
B: 没健身之前我很瘦，现在不想被别人说成是细狗。
Méi jiànshēn zhīqián wǒ hěn shòu，xiànzài bù xiǎng bèi biérén shuōchéng shì xìgǒu。
I was kind of thin before I began to train regularly. Now I dread being described as skinny and weak.