Virus kills cows from Puyallup fair

SEATTLE – A virus that spread at the Puyallup Fair in September has left about 20 cows dead, prompting an investigation by state officials.

The Herald of Everett reports that there’s no risk of the virus spreading to humans or entering the food chain.

Most of the affected cows came from Future Farmers of America clubs, state officials said.

Veterinarians believe lambs sharing the same barn as the cows spread the virus – ovine herpesvirus 2 – which causes malignant catarrhal fever.

Cattle are not able to spread the virus among each other. The disease can take as long as 20 months to develop.

State veterinarian Dr. Leonard Eldridge said the virus is in lambs’ nasal secretions, and can be spread by the air they breathe. Eldridge said the barn’s ventilation system may have spread the virus.

Eldridge said it’s unusual for such a large number of cattle to die from the disease: On average, one out of 100 cows exposed to the virus will develop the disease.

About a quarter of the cows housed in the barn in September have died.