English Idiom: Work like a horse
Work like a horse means to work very hard and can have a positive or negative meaning depending on the situation.
If you’re working very hard every day, day after day and never take a break, then working like a horse is not such a good thing.
However, if you have a goal in mind and you power through to achieve this aim, then working like a horse has a positive meaning as long as you slow down once you have reached your goal.