Is there any association between renal failure and hepatotoxic photosensitization caused by feeding foxtail millet (Setaria italica) in sheep and goats?

Photosensitivity is an abnormal skin reaction to direct sunlight exposure. Photosen sitivity occurred because of failure to excrete phylloerythrin due to hepatic dysfunction. Foxtail millet feeding can induce hepatotoxic photosensitization and influence on different organs. This study attempts to evaluate renal function and serum electrolyte status in sheep and goats experimentally feeding foxtail millet. Twelve male goats and sheep were kept in the sunlight. The animals were fed foxtail millet diet freely in a eight-week experimental period. Blood urea nitrogen (BUN), creatinine, sodium, potassium, phosphorus, magnesium, hematocrit and hemoglobin were measured until last day of experiment in a weekly manner. On the last day, the animals were euthanized and kidneys were removed for pathologic examination. Data were analyzed using repeated measurement analysis by SPSS software (version 20). Three sheep showed clinical signs of photosensitivity. BUN showed a decreasing trend from the second week of the experiment. Creatinine was increased in the six and second weeks. An increase in sodium concentration in goats from fourth week was significant. Sodium levels in sheep showed a fluctuational change. Potassium and phosphorus of sheep and phosphorus in the blood of goats were increased from the second week. Potassium in goats was constant during the time. Magnesium in the blood of sheep and goats was increased from the third and fourth weeks, respectively. The hematocrit and hemoglobin increased significantly over time. Moderate to severe hyperemia with abundant deposits of blue-violet material in the collecting ducts and mild degenerative changes in the convoluted tubules in sheep kidneys and congestion in the center of the goats’ kidney were seen. In conclusion, feeding the foxtail millet can cause renal dysfunction, and changes in the balance of some serum electrolytes.