Canine IL-17F (Interleukin-17F) is a pro-inflammatory cytokine belonging to the IL-17 family that contributes to host defense and inflammatory regulation in dogs (Canis lupus familiaris). IL-17F is produced primarily by Th17 CD4⁺ T cells, as well as by γδ T cells and other innate lymphoid populations, in response to microbial infection and immune stimulation. It signals through the IL-17 receptor complex (IL-17RA/IL-17RC) to induce expression of pro-inflammatory cytokines, chemokines such as CXCL8, and antimicrobial peptides, thereby promoting neutrophil recruitment and strengthening mucosal and barrier immunity in the respiratory, gastrointestinal, and cutaneous tissues. In healthy dogs, basal IL-17F expression is generally low but increases during bacterial and fungal infections, allergic inflammation, and chronic immune-mediated conditions. IL-17F often acts in concert with IL-17A to amplify Th17-driven inflammatory responses. In veterinary and comparative medicine research, canine IL-17F is of interest in studies of atopic dermatitis, inflammatory bowel disease, immune-mediated polyarthritis, and chronic airway disease, where Th17-associated pathways contribute to neutrophilic inflammation and tissue pathology. Characterization of canine IL-17F provides valuable insight into inflammatory signaling mechanisms and potential therapeutic targets in canine immune-mediated disease.