By Joe Verzwyvelt, MD
Winona Health
During these summer months, many concerns may strike fear in southeast Minnesotans, from the minute, such as sunburns and swimmer’s itch, to the more concerning maladies of Lyme disease and West Nile Virus. Though not a common occurrence, snake bites have also occurred in this region.
Minnesota is home to two species of venomous snakes, the timber rattlesnake and the Eastern Massasagua. Both snakes belong to the Crotalid, or rattlesnake, family and are rarely encountered and are only found in the southeastern portion of the state. The timber rattlesnake was once plentiful in the bluff region but is now endangered, secondary to habitat loss and state-sanctioned bounty hunting which ended in 1989. The last snakebite in Minnesota occurred in 2011, and there have been no deaths from a wild snakebite in Minnesota since 1868. Both species of rattlesnake are now protected by state law and it is illegal to kill, harass or collect these reptiles.
The timber rattlesnake may be yellow, gray or brownish in color with darker chevrons across the body. Their tails are much darker, often black in color, with a lighter colored rattle at the end. Opposed to non-venomous species, their heads will be triangular shaped with an elliptical-shaped pupil of the eye. When threatened they will vibrate their tails producing the characteristic and namesake sound. This time of the year, these rattlesnakes may be seen sunning themselves on a bluff ledge or rocky outcropping.
The venom found in rattlesnakes is actually a combination of multiple enzymes that cause extreme pain, swelling, bruising, skin breakdown and thinning of the blood. The venom will enter the bloodstream and can travel throughout the body. It is very infrequent that deaths occur from these bites, but they do occur.
Though encounters are very rare, it is important to implement safe practices when enjoying our outdoors. One should always watch their step and be aware of their surroundings. When hiking, use a staff or walking stick to prod ground prior to stepping or sitting. In addition, a sturdy pair of hiking boots and thick pants can help prevent envenomation if bitten.
If by chance you do receive a bite from a snake you believe to be a rattlesnake, the first thing you should do is to move yourself a safe distance from the snake and remain calm. Call for help immediately, if you are able to do so, for treatment at a local emergency department. If you have any jewelry, rings or other tight fitting apparel on the limb affected, it should be removed as well in the event of swelling. This limb should also be kept immobilized and in a comfortable position below the level of the heart.
Contrary to popular belief, one should not cut or suction the snakebite nor should one apply ice or tourniquets. Some evidence suggests a wide and lightly wrapped band around the limb above the bite site may help prevent spread of the venom.
An antivenin, CroFab©, does exist and is available at many hospitals in the region. It acts by binding to the rattlesnake venom and neutralizing it. This antidote is most effective if administered within six hours of the initial bite and may require multiple doses.
So go forth and enjoy our beautiful region knowing you have the information you need if you encounter one of our usually unseen native creatures.
Joe Verzwyvelt, MD, is an Emergency Medicine physician at Winona Health. In his free time, he enjoys hiking, hunting, fishing and camping.