LAS VEGAS - The Nevada Department of Wildlife has confirmed that the same strain of Mycoplasma ovipneumoniae, the pathogen that led to a pneumonia outbreak in the River Mountain herd of desert bighorn sheep in August 2013, has been found in bighorn sheep herds living in the Eldorado, McCullough and Spring Mountain ranges.
While this information alone was bad news for state wildlife biologists, test results also confirmed that a second strain of Mycoplasma ovipneumoniae is also present in the Spring Mountain sheep herd. The same strain that led to a deadly pneumonia outbreak among bighorn sheep in the Old Dad and Marble Mountain ranges of California. That outbreak has led to the death of bighorn sheep in those California ranges since it began in spring 2013.
"This is a worst case scenario," said Pat Cummings, wildlife biologist for NDOW. "Given the geography between the Spring Mountains and the outbreak area in California, we were concerned this might be possible, especially with the ability of bighorn rams to cover vast amounts of territory in their wanderings. There is no way to limit these animals' movements."
In addition to confirming the presence of Mycoplasma ovipneumoniae in the three ranges, NDOW also positively identified one case of pneumonia. According to Dr. Peregrine Wolff, the state wildlife veterinarian, testing efforts "confirmed pneumonia in a lamb from the Eldorado Mountains. In September we also confirmed pneumonia in a lamb from the River Mountain herd."
Currently there is no means of medically treating infected animals or inoculating those that are healthy. The next steps for NDOW involve continued monitoring of the disease event's effects on the overall sheep population within the affected areas while also seeking to identify the event's geographic scope.
"As we learn more, we will also have to adjust our management activities and conservation efforts," Cummings said.
The pathogens' discovery came about through testing conducted by the Southern Nevada Bighorn Sheep Disease Investigation Project, a partnership involving NDOW, the Fraternity of the Desert Bighorn and the Wild Sheep Foundation. The partnership was created to determine whether those pathogens known to cause pneumonia in bighorn sheep are present in herds beyond the River Mountains. Field observations and other available information, including the results of fall 2013 aerial population surveys, led project members to focus their efforts specifically on the Eldorado, McCullough and Spring Mountain ranges.
In November, the partnership tested a total of 33 animals, 10 each in the Eldorado and McCullough ranges and 13 in the Spring Mountains. Only one extremely sick bighorn sheep that was captured in the Eldorado Mountains was necropsied, the others all were tested using non-lethal means.
"We are very concerned the Mycoplasma ovipneumoniae could spread to other mountain ranges. The strain type is similar between the River Mountains and the additional three ranges that we tested. This likely occurred from infected sheep moving between those ranges," said Wolff.
Outdoor recreationists can help by letting NDOW know if they see sick or dead bighorn sheep during their wanderings. Wolff said it would be a big help if recreationists can take a picture and also record their location with their phone or GPS unit. "This will allow us to get back to that location," she said.
The Nevada Department of Wildlife (NDOW) protects, restores and manages fish and wildlife, and promotes fishing, hunting, and boating safety. NDOW's wildlife and habitat conservation efforts are primarily funded by sportsmen's license and conservation fees and a federal surcharge on hunting and fishing gear. Support wildlife and habitat conservation in Nevada by purchasing a hunting, fishing or combination license. Find us on Facebook, Twitter or visit us at www.ndow.org.[[In-content Ad]]
