5. • At least 750,000
species
• Three times
number of all other
animal species
combined
• Scorpions, spiders,
ticks, Insects etc.
ARTHROPODS
6. SNAKES
A world free of snakes
• Nearly a quarter of us would go hungry
• Are important elements in the food chain
to control the rodent population- Which
destroy all major crops
The bottom line is we need
snakes to survive
7. • Snakes belong to the order of animals called
reptiles
• This group also include crocodiles, lizards, and
turtles
• Snakes maintain a fairly steady body
temperature by their behavior
• Raise their temperature by lying in the sun or
lower it by crawling into the shade
SNAKES
8. • Snakes have a
long, legless, flexible body that is
covered with dry scales
• Snake's eyes are covered by clear
scales rather than movable
eyelids; therefore, their eyes are
always open
SNAKES
9. • They repeatedly flick out their
narrow, forked tongue, using it
to bring odors to a special sense
organ in the mouth
SNAKES
10. SNAKES – EVOLUTION
• Early snakes killed their prey using
surprise attacks and by suffocating
them to death
• Snakes evolved a venom as new
weapon about 60 million years ago
11. • 3000 species of
snakes in the
world
• 375 are
venomous (10
to 15 %)
SNAKES
12. WORLD DISTRIBUTION OF SNAKES
• Occur practically all
over the
world, apart from
places like
Greenland, Iceland,
and Antarctica
• Most snakes are
found in tropical
regions
13. SNAKES – HABITAT
• Long grass
• Shrubs & hedges
• Holes & burrows
• Shady places like
under pre-
fabricated
construction
• Garbage pits
14. SNAKES – COLD BLOODED
• Do not have the ability of generating
adequate amounts of heat in order to keep
their body temperature at a constant level
• Dependent on the heat from their
surroundings and the sun to control the
temperature of their body
• Most snake species are found in the humid and
warm climes of tropical regions
15. SNAKES – SIZE
• Anaconda can
grow up to 38 feet
in length
• Brahminy blind
snake is just 2
inches
long, making it
the smallest snake
16. SNAKES – SENSE OF HEARING
• No external ears
• Probably deaf to
most sounds
• Hear by sensing
vibrations with
their belly scales
and lower jaw
17. SNAKES – SENSE OF SMELL
• Snakes use their
forked tongue to
smell
• Tongue gathers
airborne particles
18. SNAKES – COLOUR
• Dull to brilliant with striking
patterns
• Dull for camouflage
• Brightly coloured are usually
poisonous
• Use bright colours to warn
predators
• Some non-poisonous snakes
mimic the patterns and bright
colors of poisonous snakes to fool
predators
19. SNAKES – METABOLISM
• Slow rate of
metabolism
• King Cobra can
go for months
without food
20. SNAKES – MOLTING
• We shed small
quantities of old
skin continuously
• Snakes shed their
old skins in a
continuous sheet (a
process called
ecdysis)
21. SNAKES – MOLTING
• Interval between
sheds depends on
age, growth
rate, environmental
factors
• Young shed more
frequently
• Adult snakes shed
less often
22. SNAKES – CRAWLING
• The type of
movement used
depends largely on
the terrain
Concertina
Serpentine
Side – winding
Rectilinear
23. SNAKES – VENOM
• Venom is the toxic
saliva produced by
the parotid salivary
glands of the
poisonous snakes
24. • Snake venom is highly modified
saliva, and is produced by
modified saliva glands
• Proteinaceous nature of snake
venom was established by
Napoleon Bonaparte's
brother, Lucien in 1843
SNAKES – VENOM
25. • Proteins constitute the major portion of venom's
dry weight–90% or more
• Snake venom is a cocktail of hundreds, sometimes
thousands, of different proteins and enzymes
• Many of these proteins are harmless but a
percentage of them are toxins
• The makeup of these toxins varies widely from
species to species
• This complexity accounts for the widely differing
effects of snakebite
SNAKES – VENOM
29. • Venoms are rich in hydrolithic
enzymes, a complex mix of
polypeptides, nucleases, peptidases, etc
., which help digest the snake's prey
• Some of them also enhance or
contribute to the toxic effect of the
venom
SNAKES – VENOM
30. • Hemotoxin (blood toxin)
Hemotoxic venom attacks the circulatory system and
muscle tissue causing excessive
scarring, gangrene, and sometimes leads to
amputation of the affected area
This venom basically destroys tissue and blood cells
In addition to killing the prey, part of the function of
a hemotoxic venom for some animals is to aid
digestion
The venom breaks down protein in the region of the
bite, making prey easier to digest.ex : Vipers
SNAKES – VENOM
31. SNAKES – VENOM
• Vasculotoxic poison
Enzymatic
destruction of cell
membranes and
coagulation disorders
Result in
Destruction of endothelial
cells of blood vessels
Lyses of RBCs
Failure of blood clotting
32. • Neurotoxin (nerve toxin)
Neurotoxic venom attacks the
victim's central nervous system and
usually result in heart failure and/or
breathing difficulties or even total
respiratory paralysis. eg:
Cobras, Kraits, Coral Snakes
SNAKES – VENOM
33. SNAKES – VENOM
• Neuro Toxin
Acts on motor nerve
Similar manner to tubocurarine poison
Compete with acetylcholine at nicotinic receptors
Render acetylcholine inactive
Leading to muscular weakness
34. SNAKES – VENOM• Krait- Pre-synaptic action
Beta-bungarotoxin- Phospholipases A2
Inhibiting the release of acetylcholine from the
presynaptic membrane
Presynaptic nerve terminals exhibited signs of
irreversible physical damage and are devoid of synaptic
vesicles
Antivenoms & anticholinesterases have no effect
Paralysis lasts several weeks and frequently requires
prolonged MV. Recovery is dependent upon regeneration
of the terminal axon
35. SNAKES – VENOM
• Krait- Pre-synaptic action
1) Inhibiting the release of
acetylcholine from the
presynaptic membrane
2) Presynaptic nerve terminals
exhibited signs of irreversible
physical damage and are
devoid of synaptic vesicles
3) Antivenoms &
anticholinesterases have no
effect
36. SNAKES – VENOM
• Myotoxic poison
Muscular pains
Myoglobinuria
Respiratory failure
due to muscular
weakness
38. CLOBRIDAE
• Most numerous snake
family
• Two third of all snakes in
the world
• Majority are
non-poisonous
• Examples
— Corn snakes
— Rat snakes
39. • Largest (size) snakes in
the world
• Non-poisonous (Use
their strength to
constrict and kill prey)
• Three largest snakes
— African rock python
— Reticulated python
— Anaconda
BOIDAE
40. VIPERIDAE• Poisonous (Haemotoxic
- Affects blood)
• Body characteristics
— Typical triangle shaped
head
— Folding fangs
— Head covered with small
scales and nostrils are
placed vertically
• Examples
─ Copperheads, cottonmouths
and rattlesnakes
41. ELAPSIDAE
• Poisonous (Neurotoxic -
Affects nerves)
• Body characteristics
— Hollow fixed fangs in the jaw
below or in front of the eyes
— Do not have the triangle
shaped head
— Head covered with large scales
— Lateral Nostrils
• Examples
— Cobras, mambas, kraits and
the coral snake
42. • 18 feet
• Head as large as man’s hand
• Hood
• Six feet tall
49. WATER SNAKES
• If just the head is
showing, it is probably a
harmless water snake
• Almost all venomous
snakes swim with their
lungs inflated, leaving
the majority of their
bodies afloat
50. Characteristic Poisonous Nonpoisonous
Shape of head Triangular Round
Pit (+) (-)
Pupils Elliptical Round
Bite marks Fang marks 2 rows of teeth
Caudal plates Single row Double row
Color body Red ring next to yellow Alternating color
Swim in water Most of the body afloat Often only head
showing
POISONOUS / NON POISONOUS SNAKES
51. POISONOUS SNAKES IN PAKISTAN
• Rat Snake (Ptyas
mucosus) Local
Name: - Dhaman
• Indian Python
(Python molurus)
Local Name: -
Azdaha
• Indian Cobra (Naja
naja) Local Name: -
Cobra
• Leaf-nosed Viper
( Eristocophis
macmahoni) Local
Name: - Cobra
52. RISK TO HUMANS
• Species and size of the snake
• Venom injected
• Localization of the bites
• Weight & general health of
the victim
• Sensitivity to the venom
• The availability of health
facility
53. SIGNS AND SYMPTOMS
• Local effects
Fang mark at the site of injection
Intense local pain
Swelling
Oozing out of haemolyzed blood
Blisters may appear
54. SIGNS AND SYMPTOMS• General effects
Haemoglobinuria
Petechial haemorrhages
Bleeding from gums, mucus membranes
such as rectum and body orifices
Haemoptysis
Cold, clammy skin
Death due to circulatory failure
55. SIGNS AND SYMPTOMS
• Myotoxic
At the site of bite no pain and swelling
Muscle weakness
Ptosis develops
Generalized muscle paralysis
Urine is brown in colour
Respiratory muscle weakness leads to death
Hyperkalemia may result in cardiac failure
56. SIGNS AND SYMPTOMS
• Neurotoxic
Lethargy , giddiness , muscular weakness and
spreading paralysis
Increased salivation and vomiting
Ptosis and paralysis of extra ocular muscles
Breathing becomes slow and laboured
Patient remains conscious but unable to speak
Finally respiratory paralysis consequently death
57.
58. WHAT TO DO
On seeing the Snake
• Remain calm and cautious
• Get out of the way
• Call for help
• Use stick to kill the snake
by keeping a safe distance
and striking the head
59. If you are the Victim
• Be calm
• Try not to move the
effected part much
• Call for help
• Move away from snake
• Prevent further bite
• Nearest health facility
WHAT TO DO
60. If you are the helper of the
Victim
• Remain calm
• Reassure the victim
• Call for help
• Move the patient to safety
• Evacuate the patient to
the nearest health facility
• Try to kill the snake with
the help of others
WHAT TO DO
61. • There are two
important aspects
of snakebite
treatment, one is
the first-aid and
then the treatment
(antivenom serum)
TREATMENT – SNAKE BITE
63. TREATMENT
• Allaying anxiety and
fright
• Prevention of spread
of venom
• Shifting the victim to
medical aid center
• Use of antivenin
64. TREATMENT
• Allaying anxiety and Fright
To prevent the shock due to fright it is desirable
to reassure the victim by clarifying that
All snakes are not poisonous
Even poisonous snakes are not fully charged
with poison all the time
Even a snake with fully charged with poison
does not always inject it’s lethal dose
65. TREATMENT
• Prevention of spread of Venom
Immobilization
Application of tourniquet
Cleaning the wound
Local emetine injection
Incision and suction at the site
66. TREATMENT
• Prevention of spread of Venom
Immobilization
Application of tourniquet
Cleaning the wound
Local emetine injection
Incision and suction at the site
67. TREATMENT
• Wash the bitten
surface with plain
water without rubbing
• Polyvalent anti-venom
should be given
• Antibiotic & Tetanus
prophylaxis
68. TREATMENT
• Anti – Venom
Types
Specific antivenin
Polyvalent antivenin
Strength of polyvalent antivenin is
1ml will neutralize 0.6mg of dried cobra
venom, 0.45mg of dried krait venom, 0.6mg of
dried russel’s viper venom and 0.45mg of dried
saw-scaled viper venom
69. TREATMENT
• Neutralize Toxin at Tissue Level
Neostigmine and atropine administration
in elapid snakebite
Heparin and fibrinogen in viper snakebite
• Contraindications
Morphine and alcohol as these depresses
respiratory center
70. TREATMENT
• General measures
Artificial respiration
Blood Transfusion
Steroids
Antihistamines
Antibiotics
Stimulants are helpful in paralytic cases
Aspirin short acting barbiturates
71. TREATMENT
• Anti – Snake Venom (ASV)
Anti–venom is immunoglobulin (usually the
enzyme refined F(ab)2 fragment of IgG) purified
from the serum or plasma of a horse or sheep
that has been immunized with the venoms of
one or more species of snake
73. TREATMENT
• Repeat dose of Anti – Snake Venom (ASV)
Continuing absorption- due to improved blood
supply following correction of
shock, hypovolaemia etc,
After elimination of antivenom
A redistribution of venom from the tissues into
the vascular space
74. TREATMENT
• At the earliest sign of a reaction
Antivenom administration must be temporarily suspended
Adrenaline-0.1% solution, 1 in 1,000, 1 mg/ml is the effective treatment for early
anaphylactic reactions
IV hydrocortisone (adults 100 mg, children 2 mg/kg body weight). The
corticosteroid is unlikely to act for several hours, but may prevent recurrent
anaphylaxis
Increasing evidence for anti H2 antihistamines-Ranitidine – adults 50
mg, children 1 mg/kg
Start fluids, inotropes along with IV adrenaline for circulatory collapse-
5-day course of oral antihistamine/ Prednisolone.
Chlorpheniramine: 2 mg six hourly Prednisolone:
5 mg six hourly
Serum
sickness
75. DON'TS• Tight tourniquets (Tight
band / rope)
• Incisions at the site of
snake
• Local suction
• Application of herbal
medicines, cow
dung, seeds, saliva etc
• Unnecessary delaying
76. • Always remain cautious, snakes
may silently harbour anywhere
• Ankle boots be used, with
trousers tucked in the socks
• Boots should be shaken before
use
• Remove bushes, shrubs etc
lying close to the buildings
• Alter all sites that provide
cool, damp, dark habitat
• A stick and torch, be used at
night
PREVENTION OF SNAKE BITES
77. PREVENTION OF SNAKE BITES
• Never reach in to holes or
crevices
• Bedding & clothing should be
thoroughly shaken
• Mosquito nets
• Two feet deep and two feet
wide trench with vertical sides
• The trench or the sleeping
platform should be thoroughly
inspected
• Watch your step; very few
snakes bite unprovoked
79. • Black Mamba
Most deadly snake
Located in Africa and is colored dark olive or a dark
brown color with black spotting along its back
Longest fangs
Delivers quick multiple bites and flees
Venom is a cardio toxin and a fully grown Black
Mamba can deliver 100mg to 120mg.
A lethal dose of a cardio toxin to a human is 10mg to
15mg
WORLD DEADLIEST SNAKES
81. • Common Krait
Located mostly in Southeast Asia
Normally black with yellow bands around it
Can go either on land or water
Affects the nerves and produces a nerve
paralysis.
Fangs are not very long so has to chew on it’s
pray to induce the venom into the blood
stream
WORLD DEADLIEST SNAKES
83. • Russell’s Viper
Located in South Asia
Light brown with three rows of black or
brown spots bordered by yellow or white
around
Responsible for the most fatalities
Highly irritable, coils up before strike
Damage to the blood cells and tissue
WORLD DEADLIEST SNAKES
85. • Taipan
Located in Australia
Pale creamy color on the head
Light brown, dark brown, copper, or
olive
Usually stay away from humans
Defend itself
WORLD DEADLIEST SNAKES
87. • Cobra
Located in South Asia
Hood that pops up behind
Symbol on the back, looks like eyes
Either spit venom or bite
Spiting venom isn’t deadly
Severe pain and damage to eyes
WORLD DEADLIEST SNAKES
