CHEYENNE, Wyo. — A University of Wyoming researcher is warning domestic livestock producers to be on the lookout for a new virus that has been decimating cattle, goats and sheep in Europe.
The Schmallenberg virus (SBV) causes severe congenital malformations and stillbirths. It was identified in 2011 in the Netherlands. The virus is transmitted by midges, which are microscopic black biting flies.
Rob Cordery-Cotter is an assistant research scientist in UW’s Department of Animal Science. He was a visiting research scientist at the University of Nottingham School of Veterinary Medicine and Science in the United Kingdom when he saw first-hand the effects of the virus on flocks of sheep and herds of cattle.
SBV has moved through the British Isles, down the Iberian coast and now is in Russia, Turkey, the Baltics and other eastern European countries.
"It's pretty terrible to see that thing over there," Cordery-Cotter said. "It's very widespread."
The midges carry the virus, which infects pregnant animals while they are in the early stage of pregnancy, causing the congenital malformations and stillbirths.
Some sheep flocks are high-value pedigree flocks synchronized to breed at the same time. If the animals are bitten collectively by the midges, the loss of some lambs and ewes can be as high as 80 percent.
"It's hammering the producers over there," Cordery-Cotter said.
There has been no indication the virus has spread to the United States, but Cordery-Cotter wants livestock producers to be alert to the danger.
If producers see severely deformed lambs, he said, they should let the veterinarian know about it and not just throw the carcass into a trash bin.
Cordery-Cotter recently talked with veterinarians at the Animal Plant Health Inspection Service in Fort Collins, Colo., and he is scheduled to speak with the Wyoming Livestock Board in July. He also is composing a letter to the American Veterinary Association. The letter will advise veterinarians to be suspicious if they see these types of severe birth defects and suggest they send the dead animals to diagnostic labs.
"Although SBV virus is not in the U.S., there is a lingering unease that something like it could appear," he said.
The epidemiology of SBV is similar to one type of Blue Tongue Virus that found its way into the Big Horn Basin in 2007.
The outbreak, which proved fatal for sheep, antelope, white-tailed deer and mule deer, highlighted the vulnerability of Wyoming’s robust livestock industry to trans-boundary animal diseases.
But Cordery-Cotter said the Blue Tongue virus doesn't seem to endure winters well and doesn't have the staying power SBV has. The new virus, he said, over-wintered quite well.
"The virus is endemic now in much of western Europe, meaning it's pretty much there to stay," he said.
Cordery-Cotter said a vaccine is expected to become commercially available shortly, but that it is another expense to the producer. He said the producers of purebred sheep will most likely use the vaccine.
Meanwhile, no one knows for sure where the virus came from, although one theory traces it to Africa, Cordery-Cotter said.
It's possible SBV was transmitted by an infected midge from Africa, perhaps brought to Europe in cut flowers. Many cut flowers from Africa are sold in European supermarkets and are kept in the cool, moist environments the midges like.
Cordery-Cotter said it's possible the virus could come into the U.S. in a shipping container or in the hold of an airliner.
He said it's pretty much agreed on that the virus doesn't infect humans, dogs, cats and coyotes. In Europe, it is also present in bison, alpacas and various deer species.