RENAL INJURY CAUSED BY FEEDING REDROOT PI GWEED (AMARANTHUS-RETROFLEXUS L) IN SWINE - CASE-REPORT

Clinical symptoms, patho-morphological changes and diagnostic observat ions have been reported in case of a poisoning caused by feeding redro ot pigweed (Amaranthus retroflexus L.) in a swine stock. The mortality was 36%. A stock of 50, three months old gilts kept under closed circ umstances before were moved onto a run where the fauna consisted of si gnificant amounts of redroot pigweed, as well as smaller amounts of ji mson weed (Datura stramonium) and lamb's weed (Chenopodium album). Cli nical symptoms (straggering movement, flaccid paralysis of the hind le gs, sternal recumbency,lying on their sides, coma) appeared first on t he day 6 after driving out and the majority of pigs died within a shor t period. Further deaths were observed after housing again, i. e. 18 p igs died. The pathological changes were characterized by a pale discol ourization of kidneys, retroperitoneal perirenal oedema, straw-yellow serous effusion in the thoracic and abdominal cavities. The histologic al examination revealed degeneration of tubular epithelium, necrosis a nd desquamation of the epithelial cells of renal tubules (Pig. 2) and precipitation of double refracting, possibly oxalate crystals in the c ytoplasm by polarization microscopic examination (Pig. 3). In an exper iment for diagnostic purpose, clinical symptoms could not be observed when feeding pigs of similar age only with redroot pigweed for two wee ks. However severe hydronephrosis (Fig. 4) and fibrosis, as well as pr ecipitation of oxalate crystals could be observed in the kidneys of pi gs exsanguinated 10 days later.