There is no curative treatment for viral infection or for lymphosarcoma in cattle. Consequently, producers must rely on management practices to eradicate BLV from their herd. These management practices have been used to either 1 identify BLV-infected cattle and slaughter positive reactors, or 2 detect and isolate BLV-infected cattle, then manage infected and non-infected cattle in separate herds, or 3 test animals for BLV status and then take appropriate biosafety and management measures to minimize exposure of non-infected animals to the infectious agent.
Bovine leukemia virus BLV is an oncogenic retrovirus that infects lymphocytes white blood cells. Proliferation of these virus-infected lymphocytes results in either a persistent lymphocytosis, a benign form of the disease, or neoplastic tumors that invade many different organ systems referred to as enzootic bovine leucosis or lymphosarcoma. Both beef and dairy cattle are the natural hosts for this virus. In the U.
Currently, there are no Federal regulations specific to curbing spread of bovine leukemia virus in the U. The economic consequences of BLV circulating in a cattle herd can be sizable, in terms of both direct and indirect costs incurred in the treatment and control of this disease. Direct costs include those associated with clinical lymphosarcoma lost production in cattle with clinical manifestation of disease , loss of production in sub-clinically infected animals e.
Indirect costs include those associated with loss of revenue due to restrictions of export of cattle and cattle products such as semen and embryos and cost to society for maintenance of regulatory agencies and research. Error: Javascript is disabled in this browser. This page requires Javascript. The functional role of BLV in leukaemogenesis is largely unknown.
The presence of the viral genome seems to be necessary for the maintenance of the transformed state, but not its continuous expression nor an LTR-mediated promotion of transcription of cellular genes. No oncogene is carried by the virus. Although bovine leukosis is not of major economic importance, its eradication is desirable and feasible in countries with a relatively low incidence, by means of testing and elimination.
For endemic situations vaccination would be preferable, and distinct possibilities exist for the development of gp51 based vaccines. In Wales, contact In Scotland, contact your local Field Services Office. Failure to do so is an offence. Internal tumours may only become apparent once cattle have been killed and butchered, so abattoir workers should look out for them. If tumours are spotted on a carcass, the abattoir must keep the carcass on site and report it to the APHA so it can be examined.
You can help prevent the disease by practising strict biosecurity on your premises. If you report suspicion of enzootic bovine leukosis APHA vets will investigate. If the disease is confirmed the outbreak will be controlled in line with the contingency plan for exotic notifiable diseases. Controls to prevent disease. What happens when a notifiable disease is suspected or confirmed.
Contact details for reporting a notifiable disease updated. Book your coronavirus vaccination and booster dose on the NHS website. To help us improve GOV.
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