Authorities have indicated to media that criminal charges are likely to follow.
The dead horses were found on Tuesday in a visit by staff of the Rowan County Sherriff's Department and the animal health division of the Kentucky Department of Agriculture.
Eleven dead animals were found in a barn and 20 more in a pasture.
Ten horses were found alive but in poor condition and are under the care of the Lewis County Humane Society.
Authorities moved to bury the dead animals.
Some reports have suggested the owner of the animals has been ill and unable to care for them.