A disturbing undercover investigation at a Michigan lab has revealed three dozen beagles have been force-fed fungicides as part of a year-long experiment that will ultimately end in their deaths, the Humane Society of the United States said.

The goal of the study, which is being conducted at Charles River Laboratories in Mattawan, is to examine damage to the dogs bodies, according to the animal protection organization. It is being carried out on behalf of Corteva Agriscience, an agriculture division of DowDuPont.

The dogs who dont die from the poison throughout the tests are scheduled to be euthanized in early July, the Humane Society said this week .