• Korean Journal of Veterinary Service
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• v.29 no.2
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• pp.89-96
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• 2006

Bovine viral leukosis is a viral disease of cattle characterized by the development of tumors in the lymphatic tissue. A female Holstein, 3-year-old, was submitted for diagnosis at the Diagnostic laboratory, Chonbuk National University. Clinical sign of the affected animal showed emaciation, enlargement of superficial lymph node and mild diarrhea. Remarkable lesions were enlargement of many internal lymph nodes. Histopathology revealed excessive neoplastic lymphoid cells characteristic of BVL infection. Subsequently, serums from all cattle were collected and serological examination was done where a 85% seropositive rate was detected using ELISA test. ELISA method showed a comparatively 75% higher detection rate than the agar gel immunodiffusion (AGID) test (85% vs 40%). Serologically positive cattle were variably detected in all ages from under 1 year to over 6 year of age. Hematological examination consistently showed leukocytosis and a differential lymphocytosis of seropositive cattle. Detailed comparative pathological and serological data diagnosed the presence of bovine viral leukosis.

• Korean Journal of Veterinary Research
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• v.22 no.1
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• pp.63-66
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• 1982

Authors encountered a case of bovine viral leukosis in a young cattle (10 months old) with the following findings; Main clinical symptoms observed were emaciation, digestive disorder, and marked enlargement of superficial lymph nodes. Biopsied specimen of the lymph nodes revealed characteristic histological picture of bovine leukosis. A severe degree of leukocytosis (108,000/cmm) accompanied by marked lympocytosis (96%=103,680/cmm) was detected from the hematological examination of peripheral blood. Most of the lympocytes(94%=101,520) were large-sized, immature, and abnormal in their morphology. In addition, a pronounced anemia (1.78 million/cmm) without regenerative evidence of erythrocyte was noted. The serum of the patient showed positive reaction against gp antigen of bovine leukosis virus in agar-gel diffusion test.

• Korean Journal of Veterinary Service
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• v.32 no.2
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• pp.111-117
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• 2009

Farmed deer could be susceptible carrier to bovine viral infectious disease. But unfortunately, there has not been an overall study over this subject in Korea so far. Therefore, a study was conducted to see serum antibodies to bovine leukosis, food and mouth disease, bovine viral diarrhea and infectious bovine rhinotracheitis in deer using the sera of farmed deer. As a result, two deer in a farms showed positive in bovine leukosis antibodies, using ELISA. For wild water deer, no antibodies were found for those diseases. As a result, it can be assumed that deer were relatively low rate of exposure to highly contagious disease such as viral bovine infectious disease in Korea. As this study was conducted over limited in number of subject and regions, continued study should be carried out in order to prevent and control the interspecies transmission in the future.

• Applied Microscopy
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• v.35 no.1
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• pp.23-30
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• 2005

Many studies have been performed on the bovine leukemia virus (BLV) since bovine leukosis had been reported in 1968 in Korea. However, there was no report on the ultrastructural examination of BLV. An attempt to detect C-type viral particles in the cultured peripheral blood lymphocytes of Holstein-Friesian dairy cattle, was made to determine whether in vitro viral expression might be used as a reliable method to identify the cow which is likely to transmit BLV. In transmission electron microscopic (TEM) examination, the virus particles were found predominantly outside of the lymphocytes even though a few particles were also observed within the membrane bound cytoplasmic vacuoles. All of them were C-type particles consisting of a central, electron-dense core separated by a clear area from a limiting envelope with a unit membrane structure. Virus particles were easily detected in the lymphocyte which was cultured with medium supplemented with either T-lymphocyte mitogen (conconavalin A) or B-lymphocyte mitogen (lipopolysaccharide). Identical viral particles, although fewer, were also consistently present in the lymphocytes cultured with medium which was containing foetal bovine serum (FBS) only and which was containing neither FBS or mitogen. By contrast, no virus particle was detected in extensive examination of lymphocytes before culture. In conclusion, the BLV cultivation and detection methods established in this study could be used as a tool to identify and eliminate the cattle which can transmit the BLV.