Lesions of perirenal hemorrhage syndrome in growing turkeys.

Turkeys from six market flocks were examined at 8 to 19 weeks of age to assess morphologic lesions of perirenal hemorrhage syndrome (PHS). PHS was diagnosed in 165 of 715 turkeys necropsied, and 82 turkeys served as age- and weight-matched controls. The most consistent gross findings were rounded pectoral muscles of normal color, ingesta-filled crops and gizzards, variable retroperitoneal perirenal hemorrhage, a swollen dark red and light purple spleen, congested intestinal blood vessels, and pulmonary edema and/or hemorrhage. The main histologic lesions of PHS were perivascular edema in lungs and kidneys, vascular congestion of various organs, renal perivenous hemorrhage, and proliferative arterial and arteriolar lesions in the spleen and kidneys that were more severe than those in controls. Heart weights, including mean relative weights of the right and combined left ventricles and interventricular septa, were significantly greater in turkeys that died with PHS than in controls. Scores for tibial dyschondroplasia and "breast blisters" were more severe in turkeys that died with PHS than in controls. The cardiovascular system appeared to be the PHS target system.