State Veterinarian Bob Gerlach told a crowd that turned out Saturday for the 46th Annual Delta Farm Forum that diseases that afflict livestock and wildlife are increasingly showing up in Alaska. He says other diseases that are on the increase in northern-tier states and Canada also moving in this direction, due to the warming climate, human-population increase and the movement of agricultural products worldwide.
Editor's note: This revised story corrects an earlier version. See note below.
Gerlach says Alaska’s cool climate and isolated location has for millennia helped protect wildlife and the people who subsist on it from many of the diseases that thrive in warmer, lower latitudes. Diseases that periodically cull large numbers of wildlife species that live there. But he says that’s changing.
“We’re not isolated from what’s going on in the world,” he said. “We’re in the center of a lot of what’s going on.”
Gerlach says diseases are now hitchhiking into Alaska through global commerce that brings livestock and other agricultural products here, as well as travelers, newcomers that their bring household pets, and wildlife species that are slowly moving north as temperatures increase here and worldwide.
“Globalization is not just moving food,” he said. “It’s moving animals, it’s moving products, and it’s moving disease.”
Gerlach told about a hundred farmers and others at this year's Farm Forum at Delta Junction High School that they need to be alert for any signs of the diseases showing up in their livestock. And he says they also need to be aware of the health of wildlife species that live or range around their farms or ranches, because wildlife is a major source of many of the diseases that can pose a threat to both animals and humans.
“We’re seeing some things that we’ve never seen in the past,” he said, “and not just in isolated areas. But they’re all over, and reaching up here, in the state.”
The main vector for most of the emerging diseases is ticks. Gerlach says different species of ticks have been showing up in recent years around Alaska, apparently because they, like their hosts, are now able to live and even thrive in the warmer climate that’s set in around the circumpolar north.
“So, introduced ticks don’t have just impact on one animal,” he said, “It has impact on a lot of different species when they move up here.”
Gerlach says researchers have in recent decades identified five new species of the parasites in Alaska. They include the Pacific black-legged tick, the American dog tick, and the brown tick. Also, the Lone Star tick, from the Southwest now showing up in northern states. He says one was recently found in Kotzebue.
“The fact that it’s up in those areas that used to be way too cold for it means it’s adapting to those areas,” he said. “And it means we’re at risk for those things, here.”
And the winter moose tick, which has decimated populations of moose in Maine and Minnesota,
“This is one that Fish and Game is extremely worried about – the moose tick or the winter moose tick,” he said. “The reason is it’s been spreading throughout Canada, it affects just not moose, but any other ungulate. So, blacktail deer, caribou, whatever.”
Gerlach says other diseases on the list of concerns include mycoplasma ovipneumonia, which is transmitted by animals in direct contact with each other. And chronic wasting disease, caused by the exchange of infectious agents called prions between animals. Gerlach says an outbreak of the wasting disease among a group of deer in Alberta and Sasketchewan.
“That population is one of the fastest-expanding populations of wild deer. There’s a 40 percent infection rate in the deer there.”
Gerlach says as the number of farms in Alaska increases, so too will the chances of disease transmission from wildlife to livestock. And he says as Alaskans grow more food locally, both for their consumption and for sale, they must maintain high standards to protect public health. He cites the case of a child in Fairbanks who contracted salmonella two years ago by handling a chick.
“So that does a risk out for someone who’s selling product from their coop in the backyard. It’s something to think about.”
Correction: This story has been revised to correct an earlier version that attributed ticks as the cause of mycoplasma ovipneumonia and chronic wasting disease. The growing incidence of those diseases are causing concern, but they're caused by other factors.
Editor's Note: On Tuesday, Gerlach clarified his remarks about the outbreak of chronic wasting disease in Alberta and Saskatchewan. He says he was referring to one particular group of deer, not to the entire population of wild deer in the provinces. He adds that the infection rate "in one group of young bachelor bucks in one particular area was much higher than the general population of animals tested." This story has been revised to reflect his clarification.