Equine CCL11 (C-C motif chemokine ligand 11), also known as eotaxin-1, is a member of the CC chemokine family that regulates eosinophil recruitment and type 2–associated immune responses in horses (Equus caballus). CCL11 is produced primarily by epithelial cells, fibroblasts, endothelial cells, and activated immune cells in response to Th2-associated cytokines such as IL-4 and IL-13, and it functions predominantly through the CCR3 receptor to promote chemotaxis and activation of eosinophils, as well as certain Th2 lymphocytes and basophils. In healthy horses, basal CCL11 expression is generally low, but levels may increase during allergic airway disease (equine asthma), parasitic infections, hypersensitivity reactions, and inflammatory conditions affecting the respiratory or gastrointestinal tract. In veterinary and comparative medicine research, equine CCL11 is particularly relevant in studies of eosinophilic inflammation, airway hyperresponsiveness, parasite immunity, and Th2-skewed immune responses. Characterization of CCL11 in horses provides valuable insight into chemokine-mediated leukocyte trafficking, allergic and parasitic disease mechanisms, and immune regulation in equine health and translational respiratory research.