This document discusses various experimental models used to test potential anti-arthritic agents, including adjuvant arthritis in rats, terpentine oil-induced edema, and formaldehyde-induced arthritis. Adjuvant arthritis is induced in rats by injecting complete Freund's adjuvant or synthetic adjuvants and results in hind paw swelling that can be monitored over time. Terpentine oil injected into rat knee joints causes acute, non-immunological edema assessed by measuring joint diameter changes. Formaldehyde injections into rat paws induce chronic, non-immunological arthritis evaluated by paw diameter increases over 10 days. These preclinical models are used to screen anti-arthritic drugs.