Government officials have confirmed that 61 wild horses died of ammonia poisoning after drinking contaminated water last week while roaming the Nellis Air Force Base range north of here.
Maxine Shane, a Bureau of Land Management spokeswoman, said autopsies performed on some of the horses showed that they died of ammonia toxicity caused by a high concentration of urea in their systems.
Air Force officials said the horses consumed the substance after an employee of Reynolds Electrical & Engineering Co. “accidentally rinsed out” a truck containing urea. Reynolds is the prime contractor for the nation’s nuclear testing program at the adjoining Nevada Test Site.
Officials said the runoff formed standing pools of water from which the horses drank.
The chemical was being used in the northwest section of the sprawling Nellis Bombing and Gunnery Range, which borders the test site.
Air Force personnel have buried the surface soil where the runoff occurred, and rock will be spread to prevent access to the soil, said Maj. Victor Andrijauskus, spokesman for Nellis Air Force Base.
The Air Force notified the BLM on Thursday that the horses were dying, Shane said. As of Friday, 31 horses had died but more deaths occurred during the weekend.
Shane said the Air Force has opened another water source on the military range to encourage the animals to leave the contaminated area.