Ovine and Caprine Interleukin-8 (IL-8), also known as CXCL8, is a highly conserved pro-inflammatory chemokine that plays a central role in innate immune responses in sheep (Ovis aries) and goats (Capra hircus), with the IL-8 protein sequence being identical between the two species. Produced by macrophages, epithelial cells, endothelial cells, and mammary gland cells in response to bacterial, viral, and inflammatory stimuli, IL-8 signals through CXCR1 and CXCR2 receptors to mediate neutrophil chemotaxis, activation, and migration to sites of infection or tissue injury. Elevated IL-8 expression is associated with economically significant small ruminant diseases including mastitis, pneumonia, caseous lymphadenitis, enteric infections, foot rot, and parasitic infestations, where neutrophil-driven inflammation contributes to both pathogen clearance and tissue pathology. In the mammary gland, IL-8 is a key mediator of somatic cell recruitment during intramammary infection and serves as an early biomarker of mastitis severity and therapeutic response. In animal health and translational research, characterization of ovine/caprine IL-8 supports studies of mucosal immunity, respiratory disease, mammary gland inflammation, and host-pathogen interactions in small ruminants, while also providing comparative insight into neutrophil-mediated inflammatory mechanisms relevant to human respiratory and inflammatory diseases.