Malignant Catarrhal Fever
The Washington Department of Agriculture’s office of the state veterinarian is in the middle of an investigation of Malignant Catarrhal Fever in cattle in the state. They have identified at least 15 head of cattle ranging in age from 4 months to 6 years that have died as a result of this viral disease. The cattle are from a number of different locations in the state. The most likely source, which the Department is still investigating, is from close contact with young lambs at the Puyallup Fair in September. Confirmatory tests have been done by the WSU diagnostic laboratory, WADDL.

The incubation period for this disease is (on average) about 50 days, which is why there has been some lag period between the date of the fair and the investigation. The number of head of cattle affected is unusual, so more information is being gathered to understand the circumstances of exposure and transmission. Private veterinary practitioners, WADDL, Veterinary Medicine Extension, and others have been working with the state veterinarian on the investigation and providing information to producers.

If you have any questions about the outbreak itself, we are referring people to the Department of Agriculture (URL on the fact sheet). For testing information, see the WADDL website (on the fact sheet). If you have questions about the disease itself or have suggestions for additional outreach efforts, please let Veterinary Medicine Extension know. We would like cattle producers (beef and dairy) to be aware of this disease and contact their veterinarian if they see any of the clinical signs. We would also like the information to reach the fair boards.

We will update you and others on the outbreak investigation with a Veterinary Extension newsletter feature article with additional details as they are revealed.

Thank you for your help.

Dale Moore
Director, Veterinary Medicine Extension
College of Veterinary Medicine, WSUVetExtension@vetmed.wsu.edu

Fact sheet on Malignant Catarrhal Fever in cattle.