Chronic toxicity of arsenic in goats: clinicobiochemical changes, pathomorphology and tissue residues.

Chronic inorganic arsenic toxicity was induced in goats by oral administration of one-fifth of the acute lethal dose 50 (ALD(50)) of sodium arsenite (25mgkg(-1) body weight) packed in gelatin capsules and given daily for 12 weeks. Clinical signs of toxicity developed from 3 week post-exposure, consisting of gastrointestinal disturbances and renal insufficiency with 100% mortality in all animals. There were significant (p<0.01) decreases in total serum protein and the albumin: globulin ratio, and increases in blood glucose and various enzymatic activities of treated animals. Toxicity also induced severe pathomorphological changes, indicative of haemorrhagic and degenerative and/or necrotic lesions in most organs. In addition, proliferative pneumonia in lungs, hyperplastic goitre in thyroid and chronic proliferative lesions in skin were observed. Liver contained the largest residues of arsenic, followed by intestine, kidneys, thyroid, abomasum, spleen, skin, lungs and lowest in brain. The intensity of pathomorphological changes was proportional to the accumulated amount of arsenic in tissues/organs.