Investigators with the Michigan Humane Society and Detroit Animal Control officers have seized 10 horses from a warehouse on the city's west side.
They're being cared for in Dansville for now.
The Humane Society said in a release Thursday that the horses were found Tuesday in "various stages of neglect or poor health."
Detroit police and the DTE Energy Theft Unit also took part in the rescue.
The Detroit News says the warehouse's roof was crumbling and its windows were broken.
Authorities are trying to determine who left the horses in the warehouse. The Humane Society says it's working with the International League for the Protection of Horses of Michigan to evaluate and finding care for the animals.
The Humane Society removed two other horses from a Detroit backyard last week.