Feline CCL3 (C-C motif chemokine ligand 3, also known as MIP-1α, macrophage inflammatory protein-1 alpha) is a pro-inflammatory chemokine that regulates recruitment and activation of immune cells during inflammatory and infectious responses in cats (Felis catus). CCL3 primarily signals through the CCR1 and CCR5 receptors, promoting chemotaxis of monocytes, macrophages, natural killer (NK) cells, dendritic cells, and activated T lymphocytes to sites of infection or tissue injury. In cats, CCL3 is produced by activated macrophages, dendritic cells, epithelial cells, and lymphocytes in response to inflammatory stimuli such as microbial products or cytokines including TNF-α and IL-1β. CCL3-mediated signaling plays an important role in feline immune responses to viral infections such as feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV), as well as inflammatory conditions including feline infectious peritonitis (FIP) caused by feline coronavirus, where recruitment of macrophages and T cells contributes to immune defense and inflammatory pathology. While CCL3-driven leukocyte recruitment supports pathogen clearance and immune activation, excessive or persistent expression may contribute to chronic inflammation and tissue damage. As a biomarker of inflammatory immune cell recruitment, feline CCL3 is studied in investigations of host–pathogen interactions, immune regulation, and disease pathogenesis relevant to feline health and comparative immunology.