Expert Blames Dog Disease for Wolf Decline
BILLINGS, Mont. Most of the gray wolf pups born in Yellowstone National Park last year have died, a federal wolf expert says, and he believes a dog disease -- parvo virus -- may be behind the dramatic loss.
Just 22 of the 69 pups born last year are still alive, said Doug Smith, the park's wolf project leader. That's the biggest drop in pup numbers since wolves were reintroduced to the park 11 years ago, with the greatest toll seen on the park's northern range. There, he said just eight of the 49 pups born last spring survived.
"It's cause for concern, a great deal of concern," he said.
Over the next few weeks, Smith said, officials plan to catch Yellowstone wolf pups and take blood samples to see if the suspicions about parvo virus are true. The disease can cause extreme diarrhea and dehydration and kill more vulnerable animals, like young pups.
Though vaccination is an option -- many domestic dogs are vaccinated to protect them against parvo -- Smith said it would be largely futile in the park.
"It requires two vaccinations to build up an immunity, and we'd have to catch every wolf," he said. "And both those things are impractical."
If parvo virus is confirmed, there is little officials can do besides monitor the population and hope exposed wolves build a natural immunity to the disease, he said.
Parvo virus also is suspected in Montana by the state's wolf program leader, Carolyn Sime.
Sime said Thursday the existence of parvo virus is "quite possible" in Montana. Some wolves, particularly in the southern part of Montana, have been affected by mange, a skin problem that can lead to excessive scratching and hair loss and is also common to dogs.
Suspicions about parvo virus are based in part on den-site monitoring and whether pups emerge in summer with their packs, she said. State wildlife officials plan to step up blood collection from wolves -- possibly even drawing from wolf carcasses dead 24 hours or less-- as part of their disease surveillance, she said.
Terry Kreeger, supervisor of veterinary services for the Wyoming Game and Fish Department, said that while parvo virus could have a noticeable effect for a number of years on wolf populations like Yellowstone's, he doesn't believe it will prove devastating.
It could, however, have implications for how wolves in the region are managed, Smith said. The number of wolves in Yellowstone dropped last year from 171 animals total to just 118, he said. The largest single-year drop prior to that was 11 -- from 1998-99, when parvo virus also was suspected, he said.
Competition among packs was also a factor in the overall population decline, with a handful believed to have totally disappeared, he said, adding that it would be wrong to count on always having a set number of packs in the park.
"A lot of people thought wolves are going to keep going (up) in Yellowstone, and they're not," he said.
Wolves in the Northern Rockies remain federally protected, although the state of Montana recently took over most management duties of wolves within its borders, and Idaho signed an agreement with the Interior Department Thursday to do the same there.
Source: Associated Press