Reproduction of acute bracken poisoning in a calf with ptaquiloside, a bracken constituent
Hirono, I.; Kono, Y.; Takahashi, K.; Yamada, K.; Niwa, H.; Ojika, M.; Kigoshi, H.; Niiyama, K.; Uosaki, Y.
Veterinary Record 115(15): 375-378
1984
ISSN/ISBN: 0042-4900 PMID: 6506412 Document Number: 227066
Ptaquiloside, a norsesquiterpene glucoside, was prepared from the boiling water extract of bracken fern. It was dissolved in 500 ml of saline and administered by drench to a 6-month-old calf at increasing dosages for six days out of every seven for the following periods: 400 mg/day for 24 days, 800 mg/day for 14 days and 1600 mg/day for four days. Neutrophilic granulocytes began to decrease greatly markedly around 50 days after the start of the experiment, and granulocytopenia continued for a further 35 days until slaughter, despite the discontinuance of ptaquiloside administration. Thrombocytes showed a relatively slow depression and reached 1 x 105/mmsuperscript 3 at the lowest level. The calf was killed 86 days after the start of adminstration of ptaquiloside. Sternal bone marrow had been replaced with fat marrow, and only small foci of erythropoietic cells and a few megakaryocytes remained.