RICHLAND, Wash. – Wildlife managers are euthanizing bighorn sheep in central Washington, where a herd has been infected with a disease that causes pneumonia. The outbreak has affected most of a herd that’s about 10 miles west of Naches.
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Washington Department of Fish and Wildlife biologists say most of the herd has been infected. In recent years, the herd was up to 200 sheep but has dwindled to 35 to 50 animals because of the disease.
Richard Harris, a wildlife manager with the department, said biologists recently have seen many sheep coughing and in poor condition.
“It looks to us that this disease has been around for awhile. We’ve seen almost as many carcasses as live sheep. So there’s animals that are dying already. We suspect that a good chunk, and perhaps all, of the Tieton herd has been infected,” Harris said.
Biologists have found about 25 dead sheep from the Tieton herd, but they have not noticed any other herds showing signs of the pneumonia.
The disease is fatal in wild bighorn sheep, and there are no treatments or preventative measures, Harris said. This type of pneumonia does not affect livestock or people.
The department estimates there are 1,650 bighorn sheep in central and eastern Washington, made up of 17 herds. In 2010, Idaho estimated it had 2,900 bighorn sheep. Oregon estimated it’s population between 3,500-3,700.
In 2010, wildlife managers euthanized bighorn sheep in the Yakima River Canyon. That population is now recovering.
Harris said that recovery was more of an exception than a rule. He said most herds take years to recover from a pneumonia outbreak because those that survive have many fewer lambs. That means the number of sheep in a herd stays low for several years before it begins to recover.
“It is very frustrating,” Harris said. “We spend a lot of money trying to bring these animals back. They’re a wonderful resource. People enjoy looking at them. A few of them get hunted, and they’re very valuable for hunters. Then, boom. The whole population can go away. It’s an unhappy situation for us.”