Crotalus Cerastes - Venom

Venom

These snakes are venomous, but possess a weaker venom than many other rattlesnakes. This, together with the smaller size of their venom glands, makes them less dangerous than their larger cousins. Still, any rattlesnake bite can be fatal and should be taken seriously and medical attention sought immediately.

Norris (2004) lists the following venom yields: 33 mg average and 63 mg maximum (Klauber, 1956), and 30 mg average and 80 mg maximum (Glenn & Straight, 1982). Brown (1973) gives a venom yield of 33 mg (Klauber, 1956) and LD₅₀ values for mice of 2.6 mg/kg IV, 3.0, 4.0, 2.3 mg/kg IP and 5.5 mg/kg SC for toxicity. With these figures, Brown calculated that the LD₅₀ for an adult human being weighing 70 kg would be 385 mg (SC).

Bites can cause pain, swelling, hemorrhagic bleb formation and ecchymosis. Any swelling is usually not particularly severe, but it can involve all of the affected limb as well as the trunk. Systemic symptoms can include nausea, dizziness, chills, coagulopathy and shock. Klauber (1997) includes an account of a man who had been bitten on the first joint of the index finger of the right hand, with only a single fang penetrating. Although the bite itself was described as no more painful than a pin prick, a doctor was seen within about 25 minutes, and 10 cc of antivenin was administered. Within 2.5 hours his entire arm was swollen and the pain was violent, "as if the arm were soaked in a bucket of boiling oil."

Ovine derived antivenom, CroFab, for North American pit viper envenomation has been widely available since 2001. Consultation with a local expert or regional poison control center should be obtained before administering antivenom. Previous antivenin (ACP) is no longer manufactured.