The midges and viruses are killed within two weeks of the onset of frost ending the transmission cycle. HD outbreaks occur in late summer and early fall when insect vectors are active. Sheep are especially susceptible to BT and can suffer severe disease and death. In domestic ruminants, such as cattle and sheep, HD is usually less severe but may cause fever, oral ulcers, and other mild signs. HD causes high mortality in northern deer with little preexisting immunity. Ulcers of the stomach (rumen and omasum) may also be present. There may be dental pad erosion or tongue ulcers as well as bloody discharge from the nasal cavity. Hemorrhage in the heart and lungs can result in respiratory distress. The viruses damage the endothelium, the lining of the blood vessels, causing small hemorrhages throughout the body. Deer with chronic infections may show hoof abnormalities, including sloughing of hoof walls. Fever causes deer to seek out water, so dead deer may be found near or in water. The acute form of HD has high mortality rates. The incubation period ranges from about 5 to 10 days. In NY, please submit reports and photos of sick or dead deer suspected of having HD using the Online EHD Reporting Form.Ĭlinical signs of HD infection in deer vary based on the serotype and whether or not animals have any preexisting immunity. There is no treatment for HD in wildlife populations, and no wildlife prevention plan currently exists. Virus identification is essential to distinguish EHD and BT from other diseases of agricultural concern, such as Foot and Mouth Disease. HD is transmitted to an animal host by Culicoides midges, tiny biting flies commonly known as “no-see-ums” or gnats that are smaller than mosquitoes and other flies.ĭiagnosis is based on the combination of clinical signs and virus testing on tissue and blood. Animals may have reduced appetite, weakness, and loss of fear of humans. Fever and edema are common, and deer often have a swollen head, neck, tongue, or eyelids. Neither EHD or BT are a disease of humans.Ĭlinical signs of HD in white-tailed deer usually begin approximately 7 days after infection. Cows typically do not show clinical signs, but sheep can suffer severe disease and death from BT infection. Domestic ruminants (sheep, cows, goats) are also susceptible to HD. Mule deer and pronghorn antelope are also affected. HD primarily affects white-tailed deer and can cause significant mortality events, particularly in the northern United States. Hemorrhagic disease (HD) is a general term for illness caused by two related viruses: Epizootic Hemorrhagic Disease virus (EHD) and bluetongue virus (BT).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |