Detail

1. Prepared By:
18 VMED – JJ 12M
18 VMED – JJ 17M
Crocodile

2. Outline
 Introduction
 Taxonomy
 General Characteristics
 Biology
 Behavior
 Restraining
 Diseases

3. Introduction
 Ancient Greek κροκόδιλος (crocodilos),
means "lizard“
 Modern English word derived from the
Classical Latin crocodīlus
 Large aquatic reptiles
 species within the subfamily of Crocodylinae
 Loosely
the alligators and caimans (family Alligatori
dae), the gharials (family Gavialidae), all
other living and fossil Crocodylomorpha

4. Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Super order: Crocodylomorpha
Order: Crocodilia
Family: Crocodilidae
Sub-Family: Crocodilinae
Genus: (i) Crocodylus (13 species)
(ii) Osteolaemus (1 species)
(Dwarf crocodile)
(iii) Mecistops (2 species)
(Slender-snouted crocodile)

5. General Characteristics
Lifespan: 35-75 years
Size
 Size greatly varies between species
 Dwarf Crocodiles grow to an adult size of just
1.5 to 1.9 m (4.9 to 6.2 ft)
 The saltwater crocodile can grow to sizes over
7 m (23 ft)
 Birth size is around 20 cm (7.9 in) long

6. General Characteristics
 Weigh
- Dwarf Crocodile: 18-20 kg
- Salt Water Crocodile: 900-1100 kg
 Teeth
- Polyodontus (80 in number)
- Replace up to 50 times in lifespan
 Bite strength: Up to 5000 lb

7. Crocodile vs Alligator
Parameter Crocodile Alligator
Habitat Prefer salt water Prefer fresh water
Snout
Longer, pointed
and ‘V’ shaped
Rounded and ‘U’
shaped
Color
Olive
green/Brown
Blackish/Grey
Teeth of lower
jaw
Visible Hidden
Feet Not webbed Webbed
Behavior More aggressive Less aggressive

8. Biology
 Biologically complex reptiles
 More closely related to birds and dinosaurs
than other reptiles
 Has a cerebral cortex and a four-chambered
heart
 Have the functional equivalent of a diaphragm
by incorporating muscles used for aquatic
locomotion into respiration
 Four species of freshwater crocodile climb trees

9. Biology
 Senses:
Eyes, ears and nostrils are located on top of the head,
allowing the crocodile to lie low in the water, almost
totally submerged and hidden from prey.
 Vision:
- eyes include cones and numerous rods
- all crocodilians can see colors
- have very good night vision, and are
mostly nocturnal hunters
 Hearing: Crocodiles can hear well

10. Biology
Olfaction:
 Very well developed sense of smell
 Aiding them to detect prey or animal carcasses
from far away.
Respiration:
 Depend on body weight
 Can hold breath 15-20 minutes under water

11. Biology
Thermoregulation:
 crucial for many bodily functions including
digestion and locomotion
 Maintains 30–33°C

12. Biology
Locomotion
Swimming

13. Biology
Locomotion
WalkingSliding

14. Biology
Locomotion
JumpingRunning

15. Biology
Defense mechanism
Hide-and-strike
The death roll
The ability to
bite

16. Biology
Reproduction
 Mate several times under water
 Females build several incomplete trial nests and
abandon them
 Lay eggs in hole or mound nests
 Egg laying takes place at night, requires 40-45
minutes
 Lay 7-45 eggs, depending on species
 Incubation period 65-90 days, depending on
temp. and species

17. Biology
Reproduction

18. Sex determination
 Crocodile doesn’t have sex chromosomes
 Sex determination depend on incubation
temperature
 ≤30°C all females
 30- 34°C produce both sexes
 ≥ 34°C all males

19. Behavior
Embryonic learning
 Mother urinate on the nest to recognize
hatchlings
 Painting flavors on the eggs influence food
selection
 Lack of imprinting
Cannibalism: a population regulatory mechanism

20. Behavior
Parental care
 Male and Female both take care of hatchlings
 When females disappear males take the part
 Guarding the nest and hatchlings,
 Helping the hatchlings out of the egg,
 Carrying them from the nest to the water,
 Responding to the distress calls of young
ones in danger

21. Behavior
Feed Selection:
 Hatchlings: insects, crustaceans, snails,
tadpoles, small frogs and fishes
 Adults: Fish, amphibians, reptiles, birds,
mammals, other crocodiles and their eggs
 In farm: Pelleted feed, domestic birds and fish

22. Behavior
Vocalization
 producing a wide variety of sounds during
various situations and conditions, depending on
species, age, size and sex
 some species can communicate over 20
different messages through vocalizations
 The sounds are chirp, contact call, distress
call, threat call, hatching call, bellowing,
annoyance call

23. Behavior
Social hierarchy:
 The largest and heaviest males are at the top, having
access to the best basking site
 Females are priority during a group feeding of a big kill
or carcass
Sexual Behavior
 The dominant male have supremacy over a group of
female called ‘harem’
 The male select one female during breeding time
 The others of ‘harem’ seeks other males for mating
 So multiple fatherhood is seen

24. Restraining

25. Restraining

26. Restraining
Chemicals used for immobilizing
Chemical Dose (mg/kg)
Duration
(hours)
Tricaine 88-99 9
Pentobarbital 7.7-8.8 2-3
Etorpine 0.4 -
Phenycyclidine 11-22 6-7
Succynylcholine 3-5 7-9
Diazepum 0.22-0.63 3

27. Sexing
 The vent is more convex in males
 In female, the cliteropenis is small with a sharp
extremity, while in the male it is large and tubular
with a more bulbous extremity

28. Diseases
Viral Diseases
 Crocodile pox
 Caiman pox
 Adenoviral Hepatitis
 Influenza C
 Eastern Encephalitis
 Coronavirus
 New Castle disease – Carrier
 West Nile disease - Zoonotic

29. Diseases
Bacterial diseases
 Salmonellosis
 Mycobacteriosis
 Erysipelothrix infection
 Clostridiosis
 Dermatophillosis
 Non-specific septicemia
Mycoplasmosis
Chlamydiosis

30. Diseases
Fungal Infection
 Aspergillosis
 Fungal dermatitis
 Generalized mycosis
 Respiratory mycosis
 Gastrointestinal mycosis
 Oral mycosis

31. Diseases
Protozoal disease
 Coccidiosis
 Cryptosporidiosis
 Hepatozoon infection
 Giardia
Parasitic diseases
 Trichinella spiralis in muscle
 Different types of Filariae
 Hook worm
 Ectoparasites (Leeches, Biting lice, Ticks and
mites)

32. Diseases
Nutritional Diseases
 Nutritional bone diseases (Rickets, Osteomalacia,
fibrous osteodystrophy, osteoporosis)
 Vitamin A defieciency
 Thiamine deficiency
 Vitamin C defieciency
 Vitamin K defieciency
 Vitamin E defieciency (Fat necrosis, White
muscle disease)

33. Diseases
Poisoning
 Botulism
 Heavy metal poisoning
 Radionuclides
 Algal toxins
 Algicides, Rodenticides
 Fire ants

34. Diseases
Multifactorial Diseases
 Enteritis
 Gout
 Runting
 Winter sores
 Chronic stress dermatitis

35. Disease
Crocodile pox
Etiology: Paramyxovirus
Clinical Sign:
 Brown crusty lesions in the oral cavity and on head
 Lesions also found in ventral and lateral aspect of the
body
Treatment:
 No specific treatment
 Antibiotic for preventing secondary bacterial infection
Prevention: A crude autogenous vaccine is used

36. Disease
Adenoviral Hepatitis
 Etiology: Adenovirus
Clinical Sign:
 No clinical sign except anorexia and lethargy
 Sometimes may be slight icterus
Treatment
 No specific treatment
 Antibiotic for preventing secondary bacterial
infection

37. Disease
Salmonellosis
Etiology: (i) Enteric form – S. enteritidis
(ii) Septicemic form – S. typhimurium
Predisposing factors:
severe stress, high environmental temparature,
frequent temparature change
Clinical Sign:
Enteric form: diarrhea, fibrinous casts
(pseudomembrane) in feces.
Septicemic form: anorexia, depression,
polyarthritis

38. Disease
Salmonellosis
Treatment:
 Antibiotic through oral or parenteral route
 Anti inflammatory drugs
 Removal of predisposing factors
Prevention:
 Elimination stressors
 Strict hygiene
 A calf paratyphoid vaccine is approached

39. Disease
Dermatophilosis
Etiology: Dermatophilus sp.
Clinical Sign:
 At initial stage, lifting of the keratin and
accumulation debris
 Followed by indentation of epidermis
 At third stage, erosion of epidermis resulting
in ulceration

40. Disease
Dermatophilosis
Treatment:
 0.5% Copper Sulfate or Zinc Sulfate
 Oxytracycline (1g active compound in per kg
feed)
Prevention:
 Strict hygiene like regular disinfection

41. Disease
Enteritis
Etiology:
 Multifactorial disease
Factors involved:
 Intestinal flora
 Inadequate temperature
 Stress
 Bacterial infection
 Virus

42. Disease
Enteritis
Clinical Sign:
 Diarrhea
 Loss of body condition
 Bloated appearance
Treatment and prevention:
 Removal of predisposing factor
 Antibiotic therapy
 Correction of feed

43. Disease
Gout
When the plasma level of uric acid rises
beyond saturation, urate crystals begin to be
deposited in the kidney, serous surfaces of
other visceral organs, musculature and joints
Predisposing factors:
 Dehydration
 Cold
 Stress
 Infection and toxic substances

44. Disease
Gout
Clinical sign:
 Generalized depression
 In renal gout, swollen kidney and hind limb
paralysis
 In arthritic gout, painful joints and animal is
reluctant to move
 White paste of uric acid in synovial fluid of
affected joints

45. Disease
Gout
Treatment:
 Rehydration in case of dehydration
 Fasting for 7-10 days if overfeeding
Prevention:
 Elimination of factors
 Appropriate feeding

46. References
 “Crocodiles: Biology, Husbandry and Diseases”
by EW Huchzermeyer
 “Manual of Exotic Pet Practice” by Mark A. Mitchell
and Thomas N. Tully, Jr.
 http://crocodilian.com/cnhc/cbd.html; retrieved on
27.07.2016
 https://www.ehp.qld.gov.au/wildlife/livingwith/croc
odiles/index.html; retrieved on 27.07.2016
 http://www.doc-developpement-
durable.org/file/Elevages/Crocodiles/; retrieved on
27.07.2016

47. THANK TO ALL