Suspected Lythrum hyssopifolia (lesser loosestrife) poisoning of cattle

Case report: Morbidity and mortality in two herds of cattle in southern New South Wales were associated with ingestion of lesser or hyssop loosestrife (Lythrum hyssopifolia). Clinical signs in adult cows included depression, listlessness, inappetence, anorexia and recumbency. Deaths occurred in 16/48 (33.3%) and 4/60 (6.7%) adult cows, but calves in both herds were unaffected. Elevated concentrations of urea and creatinine were present in the serum of one clinically affected cow and an elevated concentration of urea was detected in the aqueous humour of one cow that died. On histopathological examination, there was severe, acute necrosis of the proximal convoluted tubular epithelial cells in the kidneys of both affected cattle examined. Conclusion: There is strong evidence that lesser loosestrife is nephrotoxic for cattle.