Snakes and Snake Bites
6-1. Types of Snakes
a. Nonpoisonous Snakes. There are approximately 130 different
varieties of nonpoisonous snakes in the United States. They have oval-shaped
heads and round eyes. Unlike poisonous snakes, discussed below, nonpoisonous
snakes do not have fangs with which to inject venom. See Figure 6-1 for characteristics of a nonpoisonous snake.
b. Poisonous Snakes. Poisonous snakes are found throughout
the world, primarily in tropical to moderate climates. Within the United
States, there are four kinds: rattlesnakes, copperheads, water moccasins
(cottonmouth), and coral snakes. Poisonous snakes in other parts of the
world include sea snakes, the fer-de-lance, the bushmaster, and the
tropical rattlesnake in tropical Central America; the Malayan pit viper in
the tropical Far East; the cobra in Africa and Asia; the mamba (or black
mamba) in Central and Southern Africa; and the krait in India and
Southeast Asia. See Figure 6-2 for characteristics of a poisonous pit viper.
c. Pit Vipers (Poisonous). See Figure 6-3 for illustrations.
(1) Rattlesnakes, bushmasters, copperheads, fer-de-lance,
Malayan pit vipers, and water moccasins (cottonmouth) are called pit
vipers because of the small, deep pits between the nostrils and eyes on
each side of the head (Figure 6-2). In addition to their long, hollow fangs, these snakes have other identifying features: thick bodies, slit-like pupils
of the eyes, and flat, almost triangular-shaped heads. Color markings and
other identifying characteristics, such as rattles or a noticeable white
interior of the mouth (cottonmouth), also help distinguish these
poisonous snakes. Further identification is provided by examining the
bite pattern of the wound for signs of fang entry. Occasionally there will
be only one fang mark, as in the case of a bite on a finger or toe where
there is no room for both fangs, or when the snake has broken off a fang.
(2) The casualty's condition provides the best information
about the seriousness of the situation, or how much time has passed since
the bite occurred. Pit viper bites are characterized by severe burning
pain. Discoloration and swelling around the fang marks usually begins
within 5 to 10 minutes after the bite. If only minimal swelling occurs
within 30 minutes, the bite will almost certainly have been from a
nonpoisonous snake or possibly from a poisonous snake which did not
inject venom. The venom destroys blood cells, causing a general
discoloration of the skin. This reaction is followed by blisters and
numbness in the affected area. Other signs which can occur are weakness,
rapid pulse, nausea, shortness of breath, vomiting, and shock.
d. Corals, Cobras, Kraits, and Mambas. Corals, cobra, kraits
and mambas all belong to the same group even though they are found in
different parts of the world. All four inject their venom through short
grooved fangs, leaving a characteristic bite pattern. See Figure 6-4 for illustration of a cobra snake.
(1) The small coral snake, found in the Southeastern United
States, is brightly colored with bands of red, yellow (or almost white), and
black completely encircling the body (Figure 6-5). Other nonpoisonous snakes have the same coloring, but on the coral snake found in the United
States, the red ring always touches the yellow ring. To know the
difference between a harmless snake and the coral snake found in the
United States, remember the following:
"Red on yellow will kill a fellow, Red on black, venom will lack."
(2) The venom of corals, cobras, kraits, and mambas
produces symptoms different from those of pit vipers. Because there is
only minimal pain and swelling, many people believe that the bite is not
serious. Delayed reactions in the nervous system normally occur between
1 to 7 hours after the bite. Symptoms include blurred vision, drooping
eyelids, slurred speech, drowsiness, and increased salivation and
sweating. Nausea, vomiting, shock. respiratory difficulty, paralysis,
convulsions, and coma will usually develop if the bite is not treated
e. Sea Snakes. Sea snakes (Figure 6-6) are found in the warm water areas of the Pacific and Indian oceans, along the coasts, and at the
mouths of some larger rivers. Their venom is VERY poisonous, but their
fangs are only 1/4 inch long. The first aid outlined for land snakes also
applies to sea snakes.
If a soldier should accidentally step on or otherwise disturb a snake, it
will attempt to strike. Chances of this happening while traveling along
trails or waterways are remote if a soldier is alert and careful. Poisonous
snakes DO NOT always inject venom when they bite or strike a person.
However, all snakes may carry tetanus (lockjaw); anyone bitten by a
snake, whether poisonous or nonpoisonous, should immediately seek
medical attention. Poison is injected from the venom sacs through
grooved or hollow fangs. Depending on the species, these fangs are either
long or short. Pit vipers have long hollow fangs. These fangs are folded
against the roof of the mouth and extend when the snake strikes. This
allows them to strike quickly and then withdraw. Cobras, coral snakes
kraits, mambas, and sea snakes have short, grooved fangs. These snakes
are less effective in their attempts to bite, since they must chew after
striking to inject enough venom (poison) to be effective. See Figure 6-7 for characteristics of a poisonous snakebite. In the event you are bitten
attempt to identify and/or kill the snake. Take it to medical personnel for
inspection/identification. This provides valuable information to medical
personnel who deal with snakebites. TREAT ALL SNAKEBITES AS POISONOUS.
a. Venoms. The venoms of different snakes cause different
effects. Pit viper venoms (hemotoxins) destroy tissue and blood cells.
Cobras, adders, and coral snakes inject powerful venoms (neurotoxins)
which affect the central nervous system, causing respiratory paralysis.
Water moccasins and sea snakes have venom that is both hemotoxic and
b. Identification. The identification of poisonous snakes is very
important since medical treatment will be different for each type of venom.
Unless it can be positively identified, the snake should be killed and saved.
When this is not possible or when doing so is a serious threat to others,
identification may sometimes be difficult since many venomous snakes
resemble harmless varieties. When dealing with snakebite problems in
foreign countries, seek advice, professional or otherwise, which may help
identify species in the particular area of operations.
*c. First Aid. Get the casualty to a medical treatment facility as
soon as possible and with minimum movement. Until evacuation or
treatment is possible, have the casualty lie quietly and not move any
more than necessary. The casualty should not smoke, eat, nor drink any fluids. If the casualty has been bitten on an extremity, DO NOT elevate the limb; keep the extremity level with the body. Keep the casualty comfortable and reassure him. If the casualty is alone when
bitten, he should go to the medical facility himself rather than wait for
someone to find him. Unless the snake has been positively identified
attempt to kill it and send it with the casualty. Be sure that retrieving
the snake does not endanger anyone or delay transporting the casualty.
*(1) If the bite is on an arm or leg, place a constricting band
(narrow cravat [swathe], or narrow gauze bandage) one to two finger
breadths above and below the bite (Figure 6-8). However, if only one constricting band is available, place that band on the extremity between the bite site and casualty's heart. If the bite is on the hand or foot, place a single band above the wrist or ankle. The band should be tight enough to stop the flow of blood near the skin, but not tight enough to interfere with circulation. In other words, it should not have a
tourniquet-like affect. If no swelling is seen, place the bands about 1 inch
from either side of the bite. If swelling is present, put the bands on the
unswollen part at the edge of the swelling. If the swelling extends beyond
the band, move the band to the new edge of the swelling. (If possible,
leave the old band on, place a new one at the new edge of the swelling, and
then remove and save the old one in case the process has to be repeated.)
If possible, place an ice bag over the area of the bite. DO NOT wrap the
limb in ice or put ice directly on the skin. Cool the bite area--do not
freeze it. DO NOT stop to look for ice if it will delay evacuation and
DO NOT attempt to cut open the bite nor suck
out the venom. If the venom should
through any damaged or lacerated tissues in
your mouth, you could immediately
consciousness or even die.
(2) If the bite is located on an arm or leg, immobilize it at a
level below the heart. DO NOT elevate an arm or leg even with or above
the level of the heart.
When a splint is used to immobilize the arm or
leg, take EXTREME care to ensure the
splinting is done properly and does not bind.
Watch it closely and adjust it if any
(3) When possible, clean the area of the bite with soap and
water. DO NOT use ointments of any kind.
(4) NEVER give the casualty food, alcohol, stimulants
(coffee or tea), drugs, or tobacco.
(5) Remove rings, watches, or other jewelry from the
It may be possible, in some cases, for an
aidman who is specially trained and is
authorized to carry and use antivenin to
administer it. The use of antivenin
special risks, and only those with specialized
training should attempt to
d. Prevention. Except for a few species, snakes tend to be shy or
passive. Unless they are injured, trapped, or disturbed, snakes usually
avoid contact with humans. The harmless species are often more prone to
attack. All species of snakes are usually aggressive during their breeding
(1) Land snakes. Many snakes are active during the period
from twilight to daylight. Avoid walking as much as possible during this
- Keep your hands off rock ledges where snakes are
likely to be sunning.
- Look around carefully before sitting down,
particularly if in deep grass among rocks.
- Attempt to camp on clean, level ground. Avoid
camping near piles of brush, rocks, or other debris.
- Sleep on camping cots or anything that will keep
you off the ground. Avoid sleeping on the ground if at all possible.
- Check the other side of a large rock before stepping
over it. When looking under any rock, pull it toward you as you turn it
over so that it will shield you in case a snake is beneath it.
- Try to walk only in open areas. Avoid walking close
to rock walls or similar areas where snakes may be hiding.
- Determine when possible what species of snakes are
likely to be found in an area which you are about to enter.
- Hike with another person. Avoid hiking alone in a
snake-infested area. If bitten, it is important to have at least one
companion to perform lifesaving first aid measures and to kill the snake.
Providing the snake to medical personnel will facilitate both
identification and treatment.
- Handle freshly killed venomous snakes only with a
long tool or stick. Snakes can inflict fatal bites by reflex action even
- Wear heavy boots and clothing for some protection
from snakebite. Keep this in mind when exposed to hazardous conditions.
- Eliminate conditions under which snakes thrive:
brush, piles of trash, rocks, or logs and dense undergrowth. Controlling
their food (rodents, small animals) as much as possible is also good
(2) Sea snakes. Sea snakes may be seen in large numbers
but are not known to bite unless handled. Be aware of the areas where
they are most likely to appear and be especially alert when swimming in
these areas. Avoid swimming alone whenever possible.
All species of snakes can swim. Many can
remain under water for long periods. A bite
sustained in water is just as dangerous as one
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