A former employee says wild horses on a South Dakota ranch are dying of starvation and other causes.

The Dewey County sheriff is investigating the situation. Former International Society for the Protection of Mustangs and Burros employee Colleen Burns estimates over 30 horses have died since June.

Burns says she was fired Thursday after publicizing her allegations about conditions at the north-central South Dakota ranch. Karen Sussman, president and longtime leader of the society, says Burns is a "disgruntled employee."

Those allegations can be found here: (WARNING: GRAPHIC IMAGES)

Burns says insufficient grass and financial troubles making the society unable to buy enough hay have led to the deaths. Dewey County Sheriff Les Mayer says he ordered Sussman to feed the horses each day or risk citation or arrest.

The Dewey County Sheriff's Office says numerous people have reached out offering assistance to horses at the ranch. The Sheriff's Office updated their Facebook page with this statement:

"We are being contacted by people and groups that would like to donate for the care of the ISPMB horses. The DEWEY and ZIEBACH county States attorneys are working on setting up a fund for the hay and care for the ISPMB horses. I will post that information when it becomes available."