ANTICOAGULANT EFFECTS OF PINDONE IN THE RABBIT AND AUSTRALIAN BRUSHTAIL POSSUM

The anticoagulant and toxic effect of the rodenticide pindone were com pared in the rabbit and the Australian brushtail possum (Trichosurus v ulpecula). Six possums and six rabbits were dosed orally with 25 mg kg -1 pindone, and another five possums were dosed with 100 mg kg-1 pindo ne. Blood samples were taken before dosing and 6 days after dosing. In rabbits, the mean haematocrit was reduced from 0.41 to 0.14, the one- stage prothrombin time increased from 7.1 to more than 120 s, and acti vated partial prothrombin time increased from 26-1 to more than 180 s. These parameters were unchanged in the possums that received 25 mg kg -1. In possums that received 100 mg kg-1 the one-stage prothrombin tim e increased from 41.9 to 80.0 s and the activated partial prothrombin time increased from 30.2 to 103.9 s. The haematocrit was unchanged. Ha lf the rabbits died with extensive haemorrhaging within 6 days, but th ere was no haemorrhaging or mortality in the possums in either dose gr oup.