Enzootic bovine leukosis is a viral disease of adult cattle visually characterized by lumps and/or tumors. The bovine leukemia virus (BLV) resides in lymphocytes where it is able to "hide" from the immune system while still producing antibody titres that can be measured in the blood. Therefore, once an animal is infected with BLV, it is infected for life. The prevalence of infection in a herd may be high, but only a few animals develop fatal lymphosarcoma.
Infection is spread by contact with contaminated biological material from an infected animal. Contaminated surgical instruments, eg, dehorning gouges, ear tattooing pliers, and hypodermic needles are prime sources of transmission. As well, dairy cattle are more susceptible to BLV infection as they are in close physical contact.
An economically significant disease, BLV can effect the producer through premature culling or death as a result of lymphosarcoma. Another concern is the condemnation of carcasses at slaughter which also has a significant economic impact. Losses from export restrictions are another economic concern of BLV infection. Countries with bovine leukosis control programs require BLV-free certification prior to shipping cattle to their regions. Moreover, exporters of semen are under increasing pressure to ensure that their product is from a BLV-free animal in a BLV-free herd.
Test Method: ELISA
Sample Requirement: Serum or milk
Lab Testing Time: Same day