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This study critically reviews the literature on the prevalence and genotypic distribution of Bovine Leukemia Virus (BLV) in Asia, specifically targeting enzootic bovine leukosis, a chronic disease affecting cattle’s life and milk production along with reduced fat yield, that causing economic losses due to increased susceptibility to pathogens. European countries are eradicating BLV but Asia has a high prevalence, particularly in Asian cattle. Enzootic bovine leukosis (EBL) has distinct clinical stages: asymptomatic, persistent lymphocytosis, and lymphosarcoma. It typically occurs in adult animals, with 60% being asymptomatic during the aleukemic stage, 30% developing persistent lymphocytosis, and 5% developing lymphoma. Databases like PubMed and Google Scholar were used to search molecular and prevalence studies from 2000-2024, focusing on Asian countries. Prevalence of bovine leukosis (BL) in Asia varies significantly, with high rates in central and eastern regions. BLV is a global disease, has increased in Asia with highest prevalence in central Asia about 40.0–84.0% (Kazakhstan), 35% in Eastern Asia (Japan), and 58.3% in Southeast Asia (Thailand). BLV genotypes G1, G4, G6, G7, G12, G3, G4, G6, G7, and G10 are prevalent in various regions of Asia, with G1 being most prevalent globally. These genotypes might be spread due to animal trading, and animal domestication, affecting various countries. This review provides the current status of enzootic bovine leukosis in Asia, emphasising the need for a closed trading system to control the disease.

Parasites are ubiquitous evolutionary agents that, among other things, drive the diversification of hosts. This could also apply to animal domestication, one of the most striking evolutionary processes generating phenotypic diversity, which has recently been proposed as a parasite-mediated process (“The parasites-mediated domestication hypothesis”, PMD). The PMD is based on the fact that parasites can alter the (neuro)endocrine system (hypothalamic-pituitary-adrenal (HPA) axis, gut-brain axis, thyroid secretion, etc.), influence gene expression and ontogenetic systems, including neural crest cell development, and thus modulate physiological, behavioural and developmental components underlying the domestication. In this article, domestication is therefore placed in the context of parasite-driven diversification. The rationale for the parasite-mediated domestication process and associated diversification is supported by explanations of possible underlying mechanisms in light of the pioneering work of the Belyaev fox experiment and the later proposed hypothesis on the role of neural crest cells. Finally, a framework for plausible comparative and experimental approaches to test the PMD is proposed. Placing domestication in the context of the parasite-driven host diversification process provides a broad perspective for future research in the field of animal evolution and domestication.