Hepato-renal toxicosis characterized in sheep dosed intraruminally with snakeweed foliage (Gutierrezia spp).

To investigate the acute effects of snakeweed foliage (SW, Gutierrezia spp), 6 ruminally fistulated wethers (avg BW 78.6 kg) were dosed intraruminally (2/dose) with 454 g ground SW foliage, 227 g SW + 227 g alfalfa, or 454 g alfalfa daily for 5 d. Rumen fluid and blood samples were collected daily before SW dosage, and on day 6 the animals were euthanized and examined. At d 5, SW increased direct and indirect bilirubin indicating impaired hepatocyte function with biliary involvement and cholestasis. Gamma-glutamyl transpeptidase concentrations were elevated, and pale yellowish enlarged livers were observed in SW-dosed animals. Serum creatinine concentrations were increased 2-fold by SW, suggesting renal impairment. Rumens from dosed animals were compacted with hemorrhagic and necrotic mucosa suggesting SW-impaired rumen motility and microbial fermentation. One wether dosed with 454 g SW died after SW dosage for 2 d.