Equine CCL8 (C–C motif chemokine ligand 8, also known as MCP-2 – Monocyte Chemoattractant Protein-2) is a proinflammatory chemokine involved in leukocyte recruitment and regulation of inflammatory responses in horses (Equus caballus). CCL8 is a member of the CC chemokine family, which includes related chemokines such as CCL2 (MCP-1), CCL7 (MCP-3), and CCL13 (MCP-4) that coordinate monocyte and leukocyte trafficking during immune activation. In horses, CCL8 is produced by macrophages, fibroblasts, endothelial cells, epithelial cells, and other immune cells in response to infection, inflammatory cytokines, or tissue injury. CCL8 exerts its biological effects through interaction with chemokine receptors including CCR1, CCR2, CCR3, and CCR5, promoting chemotaxis and activation of monocytes, macrophages, dendritic cells, T lymphocytes, and eosinophils at sites of infection or inflammation. In equine health, CCL8 contributes to immune responses associated with respiratory infections, inflammatory airway disease, and other inflammatory conditions, where chemokine-mediated recruitment of leukocytes to affected tissues plays a key role in host defense and inflammation. Because horses are frequently studied in comparative immunology and respiratory disease research, equine CCL8 is investigated to better understand chemokine signaling, leukocyte trafficking, and inflammatory mechanisms relevant to both veterinary medicine and translational biomedical research.