Waiting for Frost: Bluetongue Appears in Montana Livestock and Wildlife

By Kisha Lewellyn Schlegel, 9-25-07

	Caption: An Artist's Rendition of the Bluetongue Virus

Over the weekend the mysterious bluetongue virus simultaneously appeared in parts of England and Southeastern Montana. On Sunday, the BBC reported the first case of bluetongue, also called catarrhal fever, which most likely traveled from Europe in a swarm of infected midges. The small gnat-like insects can travel up to 124 miles a day, and just one midge bite is enough to infect an animal. And while the United Kingdom’s Telegraph reports that the disease is harmless to humans, it can kill up to 70 percent of ruminants in weeks.

Meanwhile, the San Diego Union-Tribune, reported that bluetongue had been confirmed in eight flocks in six Montana counties this month. A quarantine is now in effect for sixteen eastern Montana counties, which will prevent ranchers from transporting animals at a time when lambs are usually shipped to feedlots.

While news of recent e-coli contamination in lettuce (similar to last year’s spinach scare) dominates food news, the seasonal appearance of bluetongue in the United States and the new emergence of the disease in the United Kingdom, mark the increasing pressures and concerns that farmers and ranchers face around the world. Unlike e-coli, bluetongue will not infect humans who come in contact with the disease or consume it. But it severely affects ranchers.

Bluetongue occurs most often in sheep, but also affects cattle, goats, buffalo, deer and antelope. The disease causes ulcers in the mouth and nose, and breaks down capillary walls, causing an animal to internally bleed to death. A lack of oxygen turns an animal’s tongue blue.

First recognized in South Africa in the 1800s, bluetongue most likely spread through the Straight of Gibraltar and into Europe. The disease arrived to the United States in the 1950s and just this month infected animals in Britain for the first time.

For 25 years, the presence of bluetongue in the United States has blocked export of cattle, sheep and goats to markets in Australia, New Zealand, and the European Union. While Canada accepts U.S. cattle, they require rigorous testing before the animals may cross the border. These restrictions are thought to cost ranchers who rely on export sales $125 million a year in lost trade.

The recent cases of bluetongue have put many of Montana’s public animal auctions on hold, and ranchers without pasture will be required to buy hay for animals that would normally have been sold to feedlots this time of year. The restrictions have also impacted ranchers who sell sheep locally as no transportation of stock within or outside of the affected counties is allowed. The case of bluetongue in Britain has led to similar restrictions and adds further stress to ranchers already worried about foot and mouth disease.

Bluetongue is also the source of major concern for hunters hoping to provide their own meat this season as populations of deer and antelope are suspected of being infected. On September 13th, Montana’s Fish Wildlife & Parks Department released an alert that the virus had been seen in big game populations in southeastern Montana. Domestic sheep, white-tailed deer and mule deer, antelope and elk are all susceptible to bluetongue virus, although no bluetongue deaths have been reported in elk. The virus is the suspected cause in the deaths of hundreds of animals in southeastern Montana, particularly near Roundup and Miles City. According to an article in the Great Falls Tribune, the Melstone area near the Musselshell River has been hit hardest.

Wildlife biologists are also concerned about a possible outbreak of epizootic hemorrhagic disease, or EHD, although no cases have been confirmed. Like bluetongue, EHD is transmitted by biting midges.

Hunters traveling to central and southeastern Montana are encouraged to watch for inattentive animals, particularly those staggering near water sources because the virus dehydrates animals and causes high fevers, which may lead them to seek water. Contact with and consumption of these animals will not infect humans with bluetongue or EHD, but hunters are advised to wear rubber or latex gloves when field dressing game.

While there is little that hunters or ranchers can do to prevent the spread of the disease, the restrictions will only last until October 10th when a hard frost is expected to kill off the harboring insects. And although most scientists are not concerned about an epidemic, the costs for affected ranchers will be felt from southeastern Montana to England’s verdant countryside who patiently await that first cold snap.

For information on bluetongue or EHD, and locations of wildlife outbreaks, call FWP Region 5 in Billings at 406-247-2940, or FWP Region 7 in Miles City at 406-234-0900. Information is also available from the State of Montana’s Lisa Schmidt at 406.728.0159 and Tom Daubert at 406.449.2095.