The Bureau of Land Management (BLM) is investigating the deaths of 19 wild horses at its Cañon City, Colo., Wild Horse Inmate Program facility. The BLM discovered dead horses in a pen on Dec. 3. Several other horses in the same pen exhibited signs of illness. The BLM is working with veterinarians including state and federal animal health authorities to investigate the cause of the illness.

Veterinarians have euthanized those horses in the most severe condition with a poor prognosis for recovery. Necropsies were performed on three of the dead horses at the facility, with additional horses and samples sent to the Veterinary Diagnostic Laboratory at Colorado State University in Fort Collins.

"As a precaution, we have quarantined the facility and will not ship animals out this week," said Fran Ackley, BLM Colorado Wild Horse and Bureau Program leader. "We are working with a veterinarian to determine the cause of the illness and prevent any potential spread to other wild horses at the facility."

There is no estimate of when the lab analysis will be completed. In addition to the necropsies, the BLM sent water and hay samples to a lab for testing. The horses and burros remaining at the facility are currently being fed hay from a different source as a precaution