STILLWATER, Okla. – Reports of deer exhibiting lethargy, blue tongues and ulcers and lesions on the tongue and palate have been filed in portions of Oklahoma. These are all symptoms Blue Tongue, one of a group of viruses collectively called hemorrhagic disease.

“These viruses are one of the primary diseases that infect deer in the southeastern United States. They have similar symptoms and thus are often lumped together and called blue tongue,” said Dwayne Elmore, Oklahoma State University Cooperative Extension wildlife specialist. “The disease typically becomes apparent in late summer and coincides with high numbers of certain species of biting midges during August and September.”

Animals do not transmit the disease to each other. Only biting midges are responsible for transmission.

“Not all infected animals die, and mortality rates generally are less than 25 percent, but in some cases can be higher,” Elmore said. “In severe outbreaks, deer numbers may take several years to return to pre-disease levels.”

Often, infected animals will be found lying around water sources with little fear of man or an inability to flee.  The disease poses no health risk to humans, and while cattle can be infected, they rarely exhibit signs of disease.

“Hunters are at no risk from eating meat from infected animals unless secondary bacterial infections are present,” he said. 

While there is little that can be done to prevent hemorrhagic disease, Elmore said to contact your county wildlife conservation officer if you suspect an outbreak is occurring by observing multiple deer carcasses or noting deer acting strangely.


Oklahoma State University, U.S. Department of Agriculture, State and Local Governments Cooperating: The Oklahoma Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, gender, age, disability, or status as a veteran, and is an equal opportunity employer. 

Sean Hubbard
Communications Specialist
Agricultural Communications Services
145 Agriculture North
Oklahoma State University
Stillwater, OK 74078
Phone: 405-744-4490
Fax: 405-744-5739
Email: [email protected]

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