Why are opossums immune to rattlesnake venom?
Opossums are actually immune to the venom of many pit vipers including rattlesnakes, copperheads and cottonmouths. The reason for this immunity is due to the ntihemorrhagic and antineurotoxic antibodies in their blood.
Opossums are considered ophiophagous mammals, meaning that they are snake-eating mammals. There are other snake-eating mammals such as the skunk and mongoose, birds such as snake eagles, the Secretary Bird, and some hawks, lizards such as monitor lizards, and even other snakes, such as the Central and South American mussuranas and the North American common kingsnake. The Virginia Opossum (Didelphis virginiana) has been found to have the most resistance towards snake venom. This immunity is not acquired and has probably evolved as an adaptation to predation by venomous snakes in their habitat.
An animal that is sometimes erroneously considered to be immune to snake venom is the pig. While pigs generally do not die from snake venom, they are not immune to snake venom. Instead the venom is typically absorbed by the pig’s subcutaneous fat layer. But, if the snake bite is not promptly treated, the pig can die or lose a limb due to infection. Snakes have a lot of bacteria in their mouths, which inflict very dirty bites.