Pathology of ochratoxicosis A in young broiler chicks.

Ochratoxin A (OA), a potent nephrotoxin, was fed in the diet in sublethal concentrations (2 and 4 ppm) to broiler chicks for 20 days from hatch. Its effects on growth, relative organ size and histology of the liver, kidney and lymphoid organs were investigated. In young broiler chicks, OA caused a significant enlargement of the kidney, liver and proventriculus, whereas the thymus and bursa of Fabricius were reduced in size. It principally affected the proximal convoluted tubules of the kidney causing severe distension, enlargement and hypertrophy, and it also resulted in thickening of the glomerular basement membrane. In the liver, vacuolation and glycogen accumulation in the hepatocytes were seen. The toxin also caused regression of and a drastic reduction in the lymphoid cell population in the immunological organs. The toxicity of OA was found to be dose related.