OSU study links lice with hair loss syndrome.

Byline: From The Register-Guard and news service reports

CORVALLIS - Invasive lice that originated in Africa or Asia are the likely cause of hair loss syndrome in blacktail deer - and can cause the same condition in mule deer, according to Oregon State University researchers.

In controlled tests at the E.E. Wilson Wildlife Area north of Corvallis, healthy mule deer placed in a pen with blacktail deer infested with the lice, Damalinia (subgenus Cervicola), immediately attracted the parasites and soon began exhibiting hair loss symptoms.

"The lice were on them in no time, and the mule deer began scratching and rubbing very quickly," said Bruce Coblentz, a professor of fisheries and wildlife at OSU who worked with master's student Jason Robison on the study. "And it increased steadily."

Funding for the study was provided by the Oregon Department of Fish and Wildlife, the Oregon Hunter's Association, the Blacktail Deer Foundation and the Oregon Wildlife Heritage Foundation.

Hair loss syndrome is a debilitating condition that causes blacktail deer to constantly chew at their fur. They often become emaciated and many die, particularly during cold winters or in areas where food supplies may lack sufficient nutrition. First diagnosed in blacktail deer near Puget Sound in the mid-1990s, the syndrome has since spread among blacktail deer populations on the west side of mountain ranges from northern California to southern British Columbia.

Thus far, the condition hasn't spread to mule deer populations east of the mountains, Coblentz said. But the OSU research shows that mule deer can be host animals if the conditions are right.

"So far, the syndrome hasn't hit mule deer on the east side of the Cascades," Coblentz said, "But whether it's because of elevation, cold or pure dumb luck, we don't know."

Coblentz said Damalinia (subgenus Cervicola) is a member of a family of chewing lice that originated in Africa or Asia and is found on deer and antelope there. It is not known how it came here.

"We don't know what its normal host animal is, though we can assume it's some kind of Old World (Africa or Asia) deer," Coblentz said. "It may have gotten here through imported exotic game species, the legal or illegal transportation of exotic game, or even from zoos. It's a pointed reminder of the unknown consequences of introducing non-native species."

Coblentz said there's a clear need to learn more about the lice.

"We found ourselves looking at them more closely and finding some puzzling results that we can't explain," he said.

For example, Robison and Coblentz found that lice numbers were low or nonexistent on their deer in warm weather, then skyrocketed as the weather got colder.

Lice and symptoms of hair loss disappeared by August, but both reappeared as the weather cooled.

None of the deer in the study died of hair loss syndrome, but they were probably better fed than deer in the wild.

"I think most biologists agree it is the combination of hair loss syndrome with rugged winters and lack of nutrition that provides the biggest threat to the deer," Coblentz said. Now that the lice are here, he said, the best hope is that deer build immunity like their Old World cousins have.

`In a controlled setting, you can give the deer baths and dips to kill the lice," he said. "Eradicating the lice in the wild? Not a chance."