"This is the worst one Linn County has ever seen," Mueller said. "It was bad. The sheer numbers were just overwhelming."
Tania Lynne Herring, 30, who lives at the property at 1252 SE Fourth Ave., Mill City, was charged with 30 counts of second-degree animal neglect and cited to appear in Linn County Circuit Court on Feb. 24. Herring had no previous criminal record.
The case is still under investigation and more charges may be filed, Mueller said.
The 31 horses were in immediate need of medical care to survive, he said.
All 31 animals were placed in foster care with members of Linn County Animal Rescue, a nonprofit organization that works with law enforcement.