Three hundred 1-day-old Japanese quail (Coturnix coturnix japonica) were divided into two groups of 150 each. One group was maintained on quail mash alone, whereas Fusarium verticillioides culture material (FCM) was added to quail mash in the second group from 5 days of age and supplied 150 mg FB₁/kg mash. At day 21, each group was further subdivided into two groups, yielding four groups with 75 birds apiece, which served as the control (group CX), the Salmonella Gallinarum alone group (group CS), the FB₁ alone group (group FX), and the group fed FB₁ and infected with Salmonella Gallinarum (group FS). An oral challenge with Salmonella Gallinarum organisms (2 × 10⁴ colony-forming units [cfu]/ml) was given to groups CS and FS at 21 days of age. Three quail each, were necropsied on day 21 (0 day interval) from groups CX and FX, whereas at subsequent intervals, i.e., 1, 2, 3, 5, 7, 10, 14, and 21 days postinfection (DPI), they were sacrificed from all four groups (CX, CS, FX, and FS) to study the agglutinin response to Salmonella Gallinarum and pathologic changes. The agglutinin titers to Salmonella Gallinarum in the combination group (FS) were generally lower when compared with those in group CS. A reduction in the size of spleen along with depletion of white pulp, thinning of cardiomyocytes, lymphoid cell depletion from bursal follicles, and renal tubular nephrosis were characteristic pathologic changes in group FX. In contrast, there was mild to severe enlargement of spleen accompanied by necrosis and reticuloendothelial cell hyperplasia, pericarditis, myocarditis, and focal interstitial nephritis in groups CS. Similar but more severe lesions were observed in the combination group (FS). In addition, the flabby texture of heart, hydropericardium, and ascites were mainly observed in group FS. It is concluded that continuous presence of fumonisins at 150 mg/kg diet increases the severity of Salmonella Gallinarum infection in young Japanese quail.