The master's eye makes the horse fat.

Close, informed oversight helps work and property prosper. The proverb presents an owner's regular attention as a practical force that prevents neglect and encourages proper care.

It also suggests that responsibility cannot always be delegated without supervision. Here “fat” uses an older sense of well-fed or thriving, rather than criticism of body size.

Use it when stressing that a leader, owner, or manager should remain actively attentive to entrusted work. It suits discussions of stewardship and supervision, but its hierarchical language and animal-care image may be awkward in sensitive workplace or animal-welfare contexts.