Karen Sussman, president of the International Society for the Preservation of Mustangs and Burros (ISPMB), is denying accusations that 30 mustangs died of starvation at the organization’s South Dakota facility.

Founded by Velma Johnston, also known as Wild Horse Annie, to study and preserve wild horse herds in the west, ISPMB currently manages four wild horse herds and collects data on the horses’ social structures and herd dynamics.

Sussman told TheHorse.com that on Oct. 2, former ISPMB employee Colleen Burns posted accusations on the internet that Sussman had maltreated horses at the sanctuary and that 30 animals had died allegedly of malnutrition.

Sussman said Burns had recently been fired from the organization and denied the accusations