Cattle killed by virus carried by sheep

Virus caught at fair kills cows
Fever poses no danger to humans

By BRAD WONG
P-I REPORTER

A rare outbreak of a disease called malignant catarrhal fever killed 19 cows that were housed with sheep in a Puyallup Fair barn in September, officials announced this week.

MORE INFORMATION

# If you showed cattle at the Puyallup Fair this year and have questions, or your animals are showing fever symptoms, call the state Agriculture Department at 360-902-1878.

# Fact sheets about the virus and fever can be found at goto.seattlepi.com/r1849 and vetmed.wsu.edu/mcf/index.htm .

State agriculture officials believe a herpes virus carried by the sheep was transmitted to the cows and attacked blood vessels in their organs, possibly causing the largest outbreak of its kind involving cattle in the country.

But the fever, officials stressed, cannot spread to other cows, other animals or humans, and no quarantine is needed.

"It has never had a history of jumping to humans. Science tells us that it's not a virus that transmits from animals to humans," said Leonard Eldridge, a veterinarian with the state Agriculture Department.

For the future, fair officials are considering housing cows and sheep in barns at different times, spokeswoman Karen LaFlamme said.

"We are working very diligently with the state veterinarian's office to find out what happened," she said. "It is a big concern to us."

One problem, she said, is that not much research about the virus exists. And researchers have not been able to re-create it in a laboratory to study it.

Formally known as ovine herpes 2, which most sheep carry and transmit through their noses, the virus also can infect deer, bison, pigs and water buffalo. It usually has an incubation period of 30 to 60 days.

The end result is the fever. Symptoms in livestock include sudden death, high fever, seizures, diarrhea and eye and nasal discharge, said Mike Louisell, a state agriculture spokesman.

State officials learned of some deaths Nov. 13 after a private veterinarian in Lynden notified them. An FFA member owned the cows and told the veterinarian that they had been at the fair.

This year's fair ran from Sept. 5 to 21, and the cattle that died were housed in the barn with sheep during the last five days, LaFlamme said.

The barn had 33 Highland Beef cattle, 88 cows of various breeds owned by FFA members and a dozen cattle owned by the fair, she said.

It remains unknown why some cows lived and why this happened this year, given that cows and sheep have shared barn space for years.

The dead cows ranged in age from 4 months to several years and came from Lynden, Arlington, Fife, Sequim, Centralia and other areas.

The International Association of Fairs and Expositions reported that its members have not had this type of loss in at least 100 years.

LaFlamme speculated that some cows might be more susceptible than others. "So much is unknown at this time," she said.

Because there is no vaccine or treatment to stop the fever, officials have managed the virus by making sheep free of it. This process is done at zoos.

In 2003, the fever killed half of a bison herd at a ranch in Twin Falls, Idaho. A year earlier, a bison ranch in Colorado reported virus-related deaths.
P-I reporter Brad Wong can be reached at 206-448-8137 or bradwong@seattlepi.com.