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White-tail-deer disease discovered in Ohio cattle |
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Last week it was reported that the white-tail-deer population in Illinois was infected with Epizootic Hemorrhagic Disease (EHD). You may have also seen the press release from the Ohio Department of Agriculture that EHD had been found in two cattle herds in Pike County, Ohio. The primary signs observed in the cattle have been excessive salivation or drooling, cloudy nasal discharge, moderate to severe lameness, poor appetite, and a severe drop in milk production in the dairy herd.
Like bluetongue virus, the virus of EHD does not usually cause clinical disease in cattle, but it can, according to William Shulaw, Ohio State University Extension veterinarian.
Unlike bluetongue virus, EHD virus does not appear to cause clinical disease in sheep, although it can infect this species as well. A small flock of sheep is present on one of the Ohio farms, but the animals are showing no signs of disease at this time.
It is too early to predict what will be observed this year in Ohio, but it is possible that a number of cattle herds will become infected, Shulaw said. Experience in previous outbreaks suggests that the number of animals that show signs in an infected herd may be as few as 5-10 percent. Cattle with signs of EHD usually recover within two to three weeks. Affected dairy cows may not return to their previous level of milk production until the next lactation.
Shulaw said that although most EHD infections in cattle are mild or go completely unnoticed, the virus can affect the developing calf in a pregnant animal. The most critical period for the fetus is between 70 and 120 days of gestation. Loss of the developing fetus or developmental deformities may occur if it is infected during this period. If you suspect the disease in your herd or area, consult with your veterinarian to consider the best plan for detecting possible pregnancy loss this fall.
There is no successful treatment for EHD virus infections in cattle. Shulaw suggests supportive treatment with anti-inflammatory drugs and supplemental feed may be helpful in affected animals showing severe lameness or those that go off feed. Animals recovering from the infection may harbor the virus in their blood for several weeks, which aids in the continued transmission of the virus. The biting midges that spread the virus will cease activity after the first killing frost and transmission will stop. In areas where there is good information that EHD is occurring, usually apparent by deer losses, producers may wish to step up their fly control efforts to help repel the midges until frost occurs in their area.
The views and opinions expressed in this column are those of the author and not necessarily those of Farm World. Readers with questions or comments for Steve Bartels may write to him in care of this publication.
This farm news was published in the Sept. 19, 2007 issue of Farm World, serving Indiana, Ohio, Illinois, Kentucky, Michigan and Tennessee. |
9/19/2007 |
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