Chronic oral administration of docosahexaenoic acid reduces knee edema in arthritis induced by Complete Freund’s Adjuvant. To determine knee edema of the affected limb, the diameter across the arthritic knee joint was measured and compared to its contralateral knee joint at days 0, 14, 18 and 25 following initial Complete Freund’s Adjuvant (CFA) injection. (A) Docosahexaenoic acid (DHA) was given daily by oral administration (p.o.) from day 15 until day 25 after CFA injection. (B) Knee edema was significantly reduced at 10, 30 and 100 mg/kg doses of DHA in mice that received CFA injections compared to CFA-injected mice treated with vehicle. Each bar represents the mean ± SEM. *P < 0.05 vs. intraarticular (i.a.) CFA + p.o. vehicle by two-way repeated-measures analysis of variance followed by post hoc Bonferroni correction.