Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Risk factors for enzootic leukosis in dairy cattle from the Brazilian Amazon

Silva, Tamyres Izarelly Barbosa daMelchior, Leonardo Augusto KoharaSantos, Priscila SouzaReckziegel, Guilherme HenriqueGomes, Yuri AlmeidaFernandes, Artur Cesar CarvalhoSilva, Daniel Dias daBaptista Filho, Luiz Carlos FontesMelo, Lúcio Esmeraldo Honório de

Background: Enzootic bovine leukosis (EBL) is a viral and lymphoproliferative disease that attributes negative economicimpacts to dairy farming. The immunosuppressive condition of these bovines favors the development of bacterial diseases such as tuberculosis, brucellosis, and bovine leptospirosis, which implications to the public health given that theyare zoonosis. Diagnosis and control of EBL are neglected in cattle rearing, allowing their dissemination, especially indeveloping countries. In this sense, the objective of this study was to analyze the risk factors of EBL in dairy cattle fromthe Brazilian Amazon.Materials, Methods & Results: In order to identify the BLV-infected animals (527 serological samples), we used theagarose gel immunodiffusion serological test (IDGA) to diagnose the EBL and characterize the risk factors through theapplication of epidemiological questionnaires. We used the logistic regression test to evaluate the existence of a significantassociation between the variables. The EBL frequency in the study area was 14.42%. We detected seroreagent bovines inall municipalities evaluated with 95% of the properties showing outbreaks of the disease. The reuse of needles was therisk factor with the most significant statistical association (P < 0.01; OR = 2.16).Discussion: The origin of EBL in the Brazilian Amazon is probably related to the expansion of dairy cattle in the 1980s,which, at first, demanded the importation of cattle for the fast formation of the herds, without complying with the sanitarycriteria of animal commercialization. The frequency of EBL in the Rio Branco microregion is below the estimated nationalaverage, as well as the regional level. The reduced influx of animals due to the geographical situation of Acre, since itis an area of greater physical isolation due to forest and river barriers, may influence the observed frequency. Differentenvironmental...(AU)

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