Toxic chemicals including nitrates may have caused the deaths of 71 mustangs managed by the Nevada Bureau of Land Management on the Nellis Range west of Las Vegas.
High levels of nitrates were found in water samples taken from a pond the wild horses used for drinking on the Nellis Range north of Las Vegas.
Importance of clean, fresh water for wild mustangs
Toxic chemicals including nitrates may have caused the deaths of 71 horses managed by the Nevada Bureau of Land Management.
The chemical was also found in some of deceased horses' body fluids.
The animals died in July.
On July 25, Federal officials announced that 55 horses and an antelope had died near a watering hole on a ballistics and bombing range in central Nevada and that tissue and water samples were being tested to determine the cause of death. The area is home to approximately 250 wild horses.
In the meantime, workers fenced off the pond and set up storage tanks to provide fresh water to the wild horses.
Later the total number of dead animals was increased to 72.