Many species of animals have the capacity to produce venom. The venom has a passive defensive function in frogs, toads and salamanders, in which the venom glands are distributed in the skin. The venom reaches the highest development in snakes and is a weapon for capturing prey, for defense and also a digestive aid.

The venom glands are actually specialized salivary organs and inoculation of the venom is through the canalized or grooved teeth. The salivary secretion of the harmless snakes is equally effective against their prey species. The venom not only immobilizes the prey but aids the subsequent digestion of animal tissues. snake venom is a mixture, chiefly of proteins, varying in composition from species to species. Studies so far undertaken indicate that the biological significance of snake venom is primarily in their digestive role.

Snakes cannot chew and mix the products of their salivary glands with the tissues of their prey. Instead, they use a highly developed injection apparatus to apply digestive aids to their food.

These powerful and concentrated enzymes are extremely poisonous. For instance, the lethal dose of Russel’s viper venom for a rabbit in the body, compounds in the poison break down the connective tissues and destroy blood vessels, causing the spread of erythrocytes and serum into the tissues.

Necrosis at the site of a bite is due to the digestive properties of snake venom. A non-toxic component of the snake venom, not always present, liberates proteolytic enzymes into the victim’s body and hastens putrefaction.