The Bureau of Land Management suspects that the H3N8 equine influenza virus, a common virus in wild and domestic horses, has caused the deaths of 94 horses since April 23 at a Cañon City detention facility.
There are more than 2,500 feral horses at the facility, including most of the horses herded into the famed Sand Wash Basin herd in Moffat County last fall, but the disease is mainly spreading among horses captured in the West Douglas Herd area, five miles south of Rangement, according to a news release Thursday, April 28.
The publication says polymerase chain reaction (PCR) lab test results from two labs found the virus in several horses.
A report by USDA Animal and Plant Health Inspection Service veterinarian Dr. Albert Kane Thursday noted that while the pneumonia-like illness has been fatal for horses at West Douglas, symptoms have been mild in other horses at the facility.
Kane’s report also said West Douglas horses were partially vaccinated or unvaccinated, which could be a factor in spreading the disease. He said the initial illness occurred five to 10 days after a group of 50 horses received their first vaccinations and appeared first and most severely in that same group of horses.
The West Douglas horses were captured in early August 2021 and should have been vaccinated soon after, according to BLM Colorado spokesman Steven Hall.
“Part of our review of what happened in this situation is to determine why these horses were not vaccinated,” Hall said. “Was there a resource problem? Were there several horses in the establishment? Was there a problem with COVID? We are trying to determine what were the factors that caused these horses not to be vaccinated.
The BLM website states that “Vaccines for adult horses and burros are given and reinforced as soon as possible after the animals arrive at a corral. It’s a race against time to build immunity through vaccination as animals are increasingly exposed to these viruses and bacteria in their new environment. Unfortunately, respiratory diseases (flu, rhino and strangles) are highly contagious and difficult to control through vaccination alone. Vaccines can help limit the speed and severity of disease spread in a group setting. »
Kane’s report also suggested the West Douglas horses could have been compromised by smoke from the Oil Springs Fire, which burned 12,613 acres in the summer of 2021, including much of the range. distribution of the herd.
Thursday’s press release said 95 horses have died from the disease, but the death of a foal on April 18 was ruled unrelated. On Friday April 29, Hall said there had been no additional deaths since Thursday.
The American Wild Horse Campaignwho has been highly critical of the deaths, calls on Colorado Governor Jared Polis and state and federal policymakers to halt all roundups of feral horses until the Cañon City investigation is complete.
“The suspension of roundups is imperative,” the advocacy group said in a news release Friday, adding that a roundup is planned this summer for the Piceance-East Douglas herd outside Meeker.
The outbreak also canceled adoption events and prevented Sand Wash Basin horses from being part of the Meeker Mustang Makeover.
To reach Shelby Reardon, call 970-871-4253, email [email protected] or follow her on Twitter @ByShelbyReardon.