Swine interleukin-25 (IL-25), also known as IL-17E, is a member of the IL-17 cytokine family and functions as a regulator of type 2 immune responses through signaling via the IL-17RA/IL-17RB receptor complex, activating downstream NF-κB and MAPK pathways. In swine, IL-25 is expected to promote Th2-associated cytokine production—including IL-4, IL-5, and IL-13—supporting eosinophil recruitment, mucosal immunity, and defense against helminths and other extracellular parasites that impact herd health. In porcine health, pIL-25 likely plays a role in gastrointestinal immunity, respiratory inflammation, and barrier protection, with relevance to conditions such as parasitic enteritis, post-weaning intestinal inflammation, and components of the porcine respiratory disease complex where immune balance is critical. While beneficial in anti-parasitic responses, excessive or dysregulated IL-25 signaling may contribute to allergic-type inflammation or reduced growth performance due to chronic immune activation. Given the physiological similarities between pigs and humans, particularly in pulmonary and gastrointestinal systems, porcine IL-25 is valuable not only for improving livestock health and vaccine strategies but also as a translational large-animal model for studying type 2–driven inflammatory diseases such as asthma and allergic gastrointestinal disorders.