Abstract
The efficacy of antivenom in prevention of cardiovascular depression and coagulopathy induced by Brown Snake species (Pseudonaja textilis, Pseudonaja affinis) was investigated in anaesthetised mechanically ventilated dogs. Venom and antivenom in variable amounts were incubated together at 37°C for 30 minutes prior to intravenous injection. The dose of antivenom required to prevent severe cardiovascular depression and coagulopathy induced by Pseudonaja textilis venom was 25 times the current recommended dose for clinical use. A tenfold dose of antivenom was required to neutralise similar effects induced by Pseudonaja affinis venom. Large amounts of antivenom may be required in clinical use if coagulopathy or cardiovascular depression are present after envenomation by species of the Brown Snake genus.