Amount of venom injected by Russell's viper (Vipera russelli).

The total yield of venom (desiccated) in 25 adult V. russelli (mean length 111 +/- 1.8 cm (S.E.) ranges from 21-268 mg (127 +/- 13 mg, mean +/- S.E.) and that of 13 juvenile snakes (mean length 79 +/- 2.8 cm) is 8-79 mg (45 +/- 7 mg). The venom yield per milking correlated well with the length of the snake. The average amount of venom injected in the first bite of 31 adults (mean length 107 +/- 1.4 cm) is 63 +/- 7 mg (range 6-147 mg) and by 17 juvenile snakes (mean length 83 +/- 1.1 cm) is 41 +/- 8 mg (range 3-138 mg). Adults inject 45% of the glands' content in the first bite. More than 75 mg of venom (desiccated) was injected by 11 out of 31 adults and 2 out of 17 juvenile snakes. This indicates that in a substantial proportion of cases of envenomation, 40 ml of Burma Pharmaceutical Industry monovalent antivenom, which is commonly used, may not be adequate.