PATHOLOGY OF GOUT IN GROWING LAYERS ATTRIBUTED TO HIGH CALCIUM AND PROTEIN DIET
An outbreak of gout was investigated in a growing layers farm of 45000 birds located in Tripoli, Libya. Mortality was commenced at 39 days-old reaching to a total of 489 birds within 10 days. Post mortem was conducted and kidney tissue samples were fixed in 10% neutral formalin prior to processing. Feed samples were sent to the Animal Nutrition Department for analysis which revealed 23.47% crude protein and 3.5% calcium. Gross lesions comprised of deposition of chalky white material covering the pericardium and enlarged kidneys with necrotic foci, hemorrhage and nephrosis. Most of birds showed swollen ureter of one or both sides. Histopathologically, severe damage of tubules characterized by moderate to severe tubular dilation and necrosis and central bluish gouty deposition surrounded by radiations of needle like urate crystals followed by granulomatous reaction of lymphocytes, macrophages and fibroblasts. The collecting renal tubules, urinephric ducts and ureters were also filled by gouty deposits with epithelial hyperplastic changes and chronic inflammatory cellular reaction in their walls. The interstitial tissue showed edema, congestion, hemorrhage and lymphomononuclear cell infiltration. This gout outbreak in growing layers is attributed to high concentration of crude protein and calcium in diet.