Bluetongue is a viral disease of sheep and deer that is spread by the Culicoides species of gnat. However, there is some evidence that the virus may also be spread by re-used needles. Bluetongue can be severe in sheep and cause sudden death, abortion, and loss of wool production.

Bluetongue virus can also infect cattle and goats but often there are no clinical signs of illness. In rare cases, the disease may cause lesions of the mouth and hoof similar to Foot and Mouth Disease. Many countries will not import cattle infected with the Bluetongue virus or its antibodies, which results in economic damage to the beef industry.

Endemic Areas

Africa, the Middle East, North America, South America and parts of Asia. In the United States, the virus is limited to southern and western states.

Clinical Signs

• Fever
• Excessive salivation
• Swollen face and ears
• Panting
• Nasal discharge
• Lesions on the mouth and hoof
• Swollen and blue-colored tongue (occasionally)
• Abortion
• Sudden death, especially in deer

Treatment

There is no specific treatment for Bluetongue. The mortality rate for sheep is almost 50 percent. Most cattle recover without incident. Any animal suspected of having Bluetongue should be reported to the State Veterinarians or USDA Area Veterinarian in Charge immediately.

Prevention

There is a Bluetongue vaccination for sheep but not cattle. The spread of Bluetongue can be prevented by controlling the Culicoides gnat through pesticides and elimination of standing water. These gnats are most active at dawn and dusk so animals should be kept in a barn at these times to minimize contact.

Public Health

Bluetongue is not a public health threat.

Links

Bluetongue-USDA-APHIS

Bluetongue Disease Card-Food and Agriculture Organization of the United Nations

Bluetongue in Cattle-Utah State University

Bluetongue Photos-Food and Agriculture Organization of the United Nations