work like a dog
To work very hard. The phrase sometimes implies that the work is demeaning. I've been out here working like a dog while you sit inside sipping lemonade. Can you maybe lend a hand? I worked like a dog all summer to earn enough cash to buy my guitar, and it was all worth it.
ˌwork like a ˈdog/ˈslave/ˈTrojan
(informal) work very hard: She worked like a slave to pass her exams. OPPOSITE: not do a stroke (of work)