1. work like a dog - Verb
2. work like a dog - Phrase
work like a dog (third-person singular simple present works like a dog, present participle working like a dog, simple past and past participle worked like a dog)
(simile) To work very hard.
But in order to be the thing you want to be, you have to work like a dog at the thing you love. Frank Langella
Look like a girl, act like a lady, think like a man and work like a dog. Caroline K. Simon