Reptiles Flashcards
orders
crocodilia, chelonia, squamata
which orders and species are covered by the Dangerous Wild Animal Act
crocodilia, front-fanged poisonous snakes, and 2 species of poisonous lizards
husbandry: temperature
heliotherms actively seek sun for heat to bask
temperature has a direct impact on metabolism and immune system: most important factor of husbandry/temperature requirements change by species, age, season, and time of day
POTZ
preferred optimum temperature zone or thermal gradient
75-99 F
husbandry: lighting
broad spectrum lighting
use unfiltered sunlight when available (when outside temperature is above 70 F)
for lizards more light is better, place 2-4 tubes 12in or less from basking site, replace every 6 months
UVA light effect
help animals with normal behaviors
UVB light effect
activates vitamin D synthesis
D3 or cholecalciferol from UVB exposure is necessary for calcium absorption
basic aquatic cage
has a water filter, water thermostat, basking areas, and feeding areas
basic terrestrial cage
has UV light, basking light/ceramic heat emitter, thermometers, astroturf, humidity, hide box, water and food
humidity
too little = shedding problems (dysecdysis)
too much = fungal infections
using soaks allows more control
what are some ways you can get an anorexic animal to eat?
boas and pit vipers use heat sensing pits to locate warm blooded prey so might need to warm up prey
motion can also trigger feeding, and make sure cage is in optimum temperature zone: cold snakes won’t eat
animals also won’t eat pre-shed or during shed
physical exam
evaluate body-muscle tone, motility
measure snout to vent length
skin: look for lumps/bumps, parasites, skin tenting, dysecdysis, redness
eyes: look for cloudiness
resp: check for d/c
CV: heart usually 25% down body from snout
neurologic: righting reflex, skin twitching
oral: mucosal color varies by species: pale pink-bluish, oral cavity should be moist without stringy mucus
what type of teeth do reptiles have?
polyphyodontic teeth
teeth are reabsorbed or shed and quickly replaced
anesthesia
have episodical breathing: can hold their breath up to 24 hours so need PPV: 4-8 Bpm
relaxation begins cranial to caudal and is reversed during recovery
righting reflex is the first to go, check cloacal reflex and tail pinch
use fresh O2 during recovery through an ambu bag: can tolerate hight levels of CO2
unpredictable: same dose in different animals can get different results
long recovery due to slow metabolism: maintain heat
radiology
allows us to see through shell in chelonians
DV view is good for evaluation of the internal structures
lateral view is good for lungs
skyline view is used for lungs in chelonians: cranial-caudal head on view, ideal to use horizontal beam
venipuncture
lizard: jugular, tail vein, axillary plexus
chelonian: jugular, subcarapacial sinus
snakes: tail vein, cardiocentesis, axillary plexus (caudal front leg pointing toward axilla)
heparin is the preferred anticoagulant for RBC evaluation
caudal tail vein
ventral midline of the tail, about 1/4 tail length caudal to the vent
be careful of hemipenes and musk glands
go between the scales at a 90 degree angle on the midline
injection sites
IM, intracoelomic (Ice), SQ
intracoelomic: coelomic cavity accessed through prefemoral fossa (space just cranial to pelvic limb), good for turtles/tortises
why do some people believe injections in reptiles should be administered cranial to the kidneys?
they have a renal portal system which allows blood to flow from the caudal portion of the body to the kidneys prior to returning to the heart
some owners think this may cause an issue with injections: may or may not actually be an issue
fluids administration
SQ preferred for snake and lizard fluids
can use plain ringers, Normosol, LRS (if no liver issues)
what is the best form of fluid maintenance?
soaking
how is fluid therapy done?
orally
normal stool
well-formed, high in fiber
don’t defecate frequently
what causes soft stool?
diet too high in carbohydrates and too low in fiber or parasite infection
nycotherus
normal flora in chelonians
trypanasomes parasite
normal but watch for high numbers
kalicephalus parasite
intestinal hookworm associated with anemia and malnutrition in snakes
protozoa parasites
cryptosporidium, trichmonas, coccidia, giardia
salmonella
bacteria
found in raw meat, healthy reptiles, and people
reptiles carry normally in digestive tract
people can get sick from reptile contact or get it subclinically
chelonia
family: testunidae (tortoise)
protected species: Gopher, Texas, Desert
most primitive group of reptiles
tortoise is terrestrial, turtles are aquatic or semiaquatic except box turtle is terrestrial
sulcata tortoise
can get up to 200 lbs
leopard tortoise
can get above 60 lbs
radiated tortoises
live up to 50 years
from Madagascar
critically endangered
red foot and yellow foot tortoises
from South America
require 70% humidity
box turtle
terrestrial, protected in some areas, has a hinged plastrom
Blanding’s turtle
black with yellowish spots, very long neck and a bright yellow chin and throat, head is dark with short rounded snout and a notched upper jaw
terrapin turtle
lives in swamp water
red eared slider turtle
most popular pet turtle
lives 20-30 years
pond/river turtle
cheloniidae family
sea turtles
females must come ashore to lay eggs in sand
Kemp’s Ridley turtle
sea turtle
critically endangered, have primarily 1 breeding area in the gulf of Mexico, females all lay eggs at once
Hawksbill turtle
endangered sea turtle
used for shell trade
sponges are primary food source so loss of coral reef can lead to difficulties getting food
cape canaveral turtle
sea turtle
“dark skies” during nesting
leatherback turtle
sea turtle
largest turtle in the world
only 1 that lack scales and hard shell
has rubbery skin over interlocking bones
turtle shell anatomy
carapace = dorsal shell - keratin covering up to 50 bones including nuchial (most cranial)
plastron = ventral shell - made up of 9 bones
box turtles have movable hinge between pectoral and abdominal scutes
turtle beaks
soft-shelled turtle: elongated nose
adaptations for diet
turtle respiratory system
trachea is short and bifurcates into mainstream bronchi, have complete tracheal rings
lungs are saccular and attached to carapce
head and limbs retracted into the shell and hissing = expelling air
no diaphragm
have cloacal bursa for gas exchange
aquatic turtles can also exchange gases through the mucosa of their oral cavity
soft shelled turtles exchange O2 through skin
turtle respiration
alternating body cavity pressure with leg pumping and muscular contraction and relaxation within shell
turtle circulatory system
3-chambered heart with 1 ventricle that allows mixing of oxygenated and deoxygenated blood
have a cardiac shunt believed to serve in bypassing the lungs in diving turtles
which type of turtle has uric acid as waste?
terrestrial turtles
which type of turtles have urea and NH3 as waste?
aquatic
male turtle anatomy
longer, larger tails
plastron is concave to mount female
aquatic males have long front feet nails
single, large, dark colored penis located on the floor of the cloaca and is only used for reproductive purposes - can prolapse, tx: amputate
gravid turtle
pregnant or egg-bound
turtle female reproductive system
no true uterus but have an oviduct
shells are pliable
turtle PE
mostly hands-off
evaluate weight, measurement, overall condition, activity, eyes/nares, tympanic membrane, heart auscultation, respirations
look to see how they fit their shell - edema?
hydration status: shrunken eyes = dehydrated, skin turgor can be done on dorsal aspect of neck
turtle conditions commonly seen on PE
rostral abrasions
stomatitis: mouth rot, heals slowly over several sheds, salt secretions
beak overgrowth (hyperkeratosis): swollen eyes from vitamin A deficiency
ticks commonly found around ears and in just above rear legs under shell
crocodilians
closest living relative of birds
orders: crocodile, alligator, caiman, gharial
crocodile
lighter color, long narrow nose, teeth visible with mouth closed
caiman
live in swamplands of central and South America, bony plates on belly, smaller but aggressive
gharial
freshwater crocodile of India
endangered
crocodilians anatomy
4-chambered heart
foramen of panizza located between 2 aortas, shunts blood away from lungs to heart and brain during submersion, can last up to an hour
have a lowered metabolism
squamata
lizards and snakes
suborder: sauria = lizards
loosely divided into arboreal, terrestrial, burrowing, semi-aquatic, and aquatic
monitor lizards and geckos
noted for aggression
Asian water monitor lizard is a more appropriate pet but still has a vulnerable status in the wild
which lizards are covered by the dangerous wild animals act?
venomous lizards
Mexican beaded lizard and gila monster
komodo dragon
lizard genus
largest reptile, may have some venom but appear to not need it, kill through blunt force trauma and blood loss
lizard temperament
tegus and monitor lizards are known for powerful bites
iguanas use tail and neck to attack
basic lizard anatomy
lifespan: up to 30 years in larger species
iguanas have nuchal and dorsal crests
have dewlap
coelom = no diaphragm
have renal portal system
lizard ear anatomy
no external ear
tympanic membrane is clear in some
iguanas have sub-tympanic scale
lizard eye anatomy
most lizards have movable eyelids and nictating membranes
chameleons have independent eye movement
pupil differences depending on species: round = diurnal, vertical = nocturnal
light helps with melatonin release, knowing time of day, absorption of light, and temperature control
lizard colors
variations, most adults lose bright green and become grayer/brown
males have a deep reddish orange color during mating season
can develop stress colors or darken in the sun
lizard Jacobson’s organ
sensory organ located on dorsal oral cavity
scent particles are collected on tongue and transferred to the sensory organ which detects prey pheromones
lizard cardiac anatomy
have 3-chambered heart
cardiac shunt diverts blood across the heart to bypass pulmonary circulation
the impact this shunt has on them is that they can be intermittent lung breathers but can also have periods of apnea which affects anesthesia (they can hold their breath for 24 hours)
parietal eye
“3rd eye” that some reptiles and fish have
has an unknown purpose
lizard sexing
male: larger size, has dewlap, highly developed femoral pores, paired hemipenes, probe will pass posterior much deeper than female (will only pass 2-3 scales deep in females)
hemipenal prolapse
can occur in males due to straining, post copulation, forced probing, or infection
lizard shell gland
no true uterus, eggs form in oviduct, pliable shells
snake suborder
serpentes
which types of snakes are viperids?
rattlesnake, cottonmouth, copperhead
viperid characteristics
fangs on back of upper jaw for injecting venom, can rotate fangs independently, can fold against roof of mouth when not in use
venomous
located around the world except for isolated islands
triangular shaped head
short, stout body
ovoviviparous
venom control in snakes
can deliver dry bites and carefully control how much venom is expelled per bite to conserve venom
keeled scales
seen on most snake species
aka ridged scales
splay slightly outward from body and gives the snake a rough textured appearance
snake reproduction
ovoviviparity
snake’s young hatches from eggs while inside of the snake, then the snake gives birth to live young and expels the egg remains after
elapids
cobra, coral snake, mamba
slender and agile
short fangs, hang on and chew venom into victims, venom is toxic to nervous system and paralyzes breathing center
boidae
boa constrictors are exclusively New World
can be tame in captivity
max length in captivity: 7-8ft vs wild: can get more than 12ft
pythonidae
pythons live in African/Asian and Australian tropics
ball python can get to be 5ft at most
Burmese and reticulated pythons can reach 20+ ft
snakes anatomy
have Jacobson’s organ
no eyelid or nictating membrane
spectacle or globe of eye is kept moist by harderian gland
round pupil = diurnal, vertical = nocturnal
absent external ear and no middle ear but sense vibrations from substrate on which head rests
arboreal snakes pick up aeral vibrations
buccal cavity creates mucus to coat prey
pit organs
specialized heat sensitive organs in snout of snakes that can sense infrared radiation signals
seen in boas, pythons, and vipers
snake circulatory system
position of heart correlates with arboreal, terrestrial, or aquatic habits
intracardiac shunting allows them to hold their breath
snake respiratory system
most have a single right lung and a small nonfunctioning left lung
right lung is ~1/2 or more of body length and posterior 1/3 is an air sac
breathe using negative pressure ventilation where intercostal muscles expand the ribs along the entire body dropping lung pressure while drawing in air
snake male reproductive
longer tails, more scales subcloacally
cloacal probe advances further in males
boas have vestigal pelvic spurs used in copulation as stimulation and to help position the 2 cloacas together
snake female reproductive
70% of snakes are oviparous: no placental connection, young are nourished by egg yolk
ovoviviparous is seen in places where the ground is too cold to incubate eggs
ecdysis
shedding
skin is shed in visible pieces, many reptiles eat shed
amphibians shed in pieces or whole, some do gyrations to lose shed
tortoise/turtle: shed in small pieces
snakes: shed in 1 piece, amount vaies with size
appearance and behavior during shedding
eyes will become opaque during shedding
they will become cranky, anorexic, inactive, and have fragile skin
dysecdysis
abnormality in shedding process
treatment: soak in lukewarm water for 30-60 minutes 1-2x daily
