File:Sawscaled viper.jpg

English: The saw-scaled viper is a venomous viper that lives in parts of the Middle-East and Central Asia. It is the smallest member of ‘the Big Four’ snakes – the four species of snake that cause the most deaths annually. The venom yield from individual specimens varies considerably, as does the quantity injected per bite. The mortality rate from their bites is about 20%, but due to the availability of the anti-venom, deaths are currently quite rare. The viper’s potent venom has been such a medical problem that doctors have produced nine different antivenoms that target it. Within minutes of the bite, localised swelling and pain which later spread can be felt. Haemorrhage and coagulation defects follow closely, which may lead to hypovolemic shock. The most dangerous symptoms of envenomation are blood-clotting trouble and internal bleeding, which can lead to acute kidney failure. Almost all patients develop oliguria or anuria within a few hours to as late as 6 days post bite. Antivenin therapy and intravenous hydration within hours of the bite are vital for survival.