What are the characteristics of pit vipers that distinguish them from non-venomous snakes?
According to the cited source, these snakes have “two pits (with heat-sensitive organs that assist these poor-visioned reptiles to localize their prey) are located on each side of the head, between the eye and nostril, the pupils are elliptical and vertically oriented, two curved fangs or hollow maxillary teeth are folded posterior against the palate and advance forward when the pit viper strikes, the head is relatively more triangular and the scutes, or scales, on the ventral portion caudad to the anal plate continue in a single row, whereas nonpoisonous snakes have a cleft, or double row.”
Kanaan NC, Ray J, Stewart M, et al. Wilderness Medical Society Practice Guidelines for the Treatment of Pitviper Envenomations in the United States and Canada. Wilderness & Environmental Medicine. 2015;26(4):472-487. doi:10.1016/j.wem.2015.05.007
Contributed by Zach Panzer, MD, Pediatric Emergency Medicine Fellow at Nationwide Children’s Hospital, Columbus, Ohio