Canine amphiregulin (AREG) is a member of the epidermal growth factor (EGF) family and functions as a ligand for the epidermal growth factor receptor (EGFR/ErbB1), where it regulates epithelial cell proliferation, differentiation, survival, and tissue repair. In dogs (Canis lupus familiaris), amphiregulin is produced by epithelial cells, keratinocytes, fibroblasts, airway smooth muscle cells, and activated immune cells—including Th2 cells and regulatory T cells—in response to tissue injury, inflammation, and allergic stimulation. Through activation of EGFR-dependent signaling pathways such as MAPK and PI3K/AKT, canine amphiregulin contributes to wound healing, mucosal barrier integrity, and tissue remodeling in cutaneous, respiratory, gastrointestinal, and mammary tissues. Dysregulated amphiregulin expression may be associated with chronic inflammatory diseases such as atopic dermatitis and allergic airway disease, fibrotic processes, and neoplastic conditions including mammary carcinoma, squamous cell carcinoma, and other EGFR-driven tumors. In veterinary and comparative oncology research, canine amphiregulin is particularly relevant due to the use of naturally occurring canine cancers and inflammatory diseases as translational models for human EGFR-targeted therapies. Characterizing amphiregulin expression in dogs provides valuable insight into epithelial–immune interactions, tissue repair mechanisms, and EGFR-mediated signaling in both veterinary medicine and comparative biomedical research.