The Animal Humane Society last week removed 55 horses, ponies and donkeys from a Fillmore County property. The animals had untreated wounds, severe emaciation and other health problems.
Investigators also found numerous carcasses in various states of decomposition.
A dozen horses considered to be in the most serious condition were sent to the University of Minnesota for examination. By Friday morning, four of the animals had to be euthanized. The Fillmore County attorney will determine whether charges will be filed.
"This was one of the largest and more complex operations involving horses I've seen, requiring a major effort to remove and relocate the animals," said Keith Streff, senior agent for the Humane Society.
The Humane Society had no previous calls about the property, said Jeff Moravec, director of communications. The society is trying to determine why the animals were neglected, but Moravec said the owner agreed to turn over all of them.
The horses not taken to the university were being kept temporarily at the Fillmore County Fairgrounds in Preston and eventually may be placed with new owners.