Experimental Panicum miliaceum poisoning in sheep

The aim of this study was to investigate the clinical, laboratory and necropsy findings of experimentally produced Panicum miliaceum poisoning in sheep. Ten native apparently healthy male crossbred sheep, aged about 6–8 months old were used in the experiment. The animalswere randomly divided into two groups, five sheep as control and five as experimental group. Both groups were kept outdoors, without protection against the prevailing climatic conditions. The experimental group received only P. miliaceum grass freely and water ad libitum. The control group received alfa alfa hay and water ad libitum. Blood samples were taken every 5 days by jugular venipuncture and haematological and biochemical factors (ALT, AST, ALP,GGT activities and BUN, creatinin, total bilirubin, conjugated bilirubin, albumin and protein concentrations)were measured. During the experimental period, vital signs were recorded. Sheep of experimental group showed varying degrees of yellow discoloration of visible mucus membranes. Only one case receiving P. miliaceum showed signs of photosensitization including hyperaemia, swelling of eyelids, face and submandibular edema. Therewas a non-significant decrease in the body temperature and heart and respiratory rates in the late stages of the poisoning. Affected animals maintained their appetite but there was a trend to a decrease in body mass towards the end of the experiment. All sheep euthanized on day 35 and necropsied and examined grossly and histopathologically. There were no significant differences in haematological parameters between the experimental and control groups. Clinically affected sheep had significant elevation of serum gamma glutamyl transferase, alkaline phosphatase and asparate aminotransferase activities and total bilirubin, conjugated bilirubin, blood urea nitrogen, and creatinin concentrations (p < 0.05). Serum concentrations of Na, K, Cl, and Ca showed non-significant changes. Serum inorganic phosphorus concentration was significantly increased on days 30 and 35 (p < 0.05). Necropsy of experimental group revealed apparent loss of bodyweight and moderate to severe yellow discoloration of all tissues. Microscopic examination of the liver and kidneys in experimentally poisoned animals revealed lesions with various degrees.