Reptiles and amphibians Flashcards
What is the name for retaining larval characteristics while becoming functional adults?
Paedomorphism (previously neotony)
Scientific name for axolotl
Ambystoma mexicanum
Scientific name for mudpuppy
Necturus masculosus
What genus are newts?
Notophthalmus
What is the term for the warning strategy where animals have bright colors, odors, etc to warn predators not to eat?
Aposomatism
What family is true frogs?
Ranidae
Scientific name for bullfrog
Rana (Lithobates) catebeianus
Scientific name for northern leopard frog
Lithobates pipiens
What family contains the South African clawed frog?
Pipidae (Xenopus)
Scientific name and diploid chromosome # for South African clawed frog and Western clawed frog
Xenopus laevis (36) - polyploid
Xenopus tropicalis (20) - the only diploid Xenopus
Which amphibian was historically used for pregnancy assays via injection of a pregnant woman’s urine into dorsal lymph sac of female frog which caused egg laying?
X. laevis
What is FETAX?
Frog embryo teratogenesis assay: Xenopus
Benefits of X. tropicalis for genetics
Only 20 diploid chromosomes
Short generation time
Which amphibians used to study organ regeneration?
Axolotls (Ambystoma mexicanum) and newts (Notophthalmus)
What is tiger salamander (Ambystoma tigrinum) used for in research?
Vision and retinal research
Which amphibians have ability to regurgitate easily and are used to test antiemetics?
Ranid frogs e.g. bull frogs (Rana catesbeianus) and leopard frog (Lithobates pipiens)
What is Bidder’s organ and who has it?
Males in family Bufonidae
Ovarian tissue located on the cranial pole of testis
Which family is true toad? Name a species.
Bufonidae e.g. Rhinella marina (cane toad)
Which amphibians are used to study the effects of endocrine disruptors on reproductive health?
Cane toad (Rhinella marina) – endocrine disrupter-induced gonadal abnormalities of Bidder’s organ
Which family and genus is tree frogs?
Hylidae (Hyla)
How do amphibians intake water?
Absorbed through skin
4 ways to dechlorinate water
- Age water for 24-48 hr
- Aerate water
- Add sodium thiosulfate
- Activated carbon filters
**first two do not remove chloramines
What extra step is needed for sodium thiosulfate?
Sodium thiosulfate produces ammonia –> need to add zeolites to remove excess ammonia
Which common laboratory amphibian is a hard-water species? What can be used to produce hard water?
Axolotl
Modified Holtfreter’s solution
Which disinfectant is VERY toxic to reptiles and amphibians?
Phenolic compounds
What is stocking density for frogs?
1 frog/ 3L to 4 frogs/ 5-10L;
1-5L of water/frogs
What housing temperature for Xenopus?
21-22C (70-72F)
Relative humidity for amphibians
70-80%
What is Chytrid fungus susceptible to?
- Heat 60C-140F
- Desiccation
- Virkon 1% (Peroxygen)
- 2% bleach (Halogen)
- 70% ethanol (Alcohol)
What are PIT tags?
Passive integrated transponder (PIT) tags
Implanted or injected into dorsal lymph sac or intracoelomically
ID methods for amphibians
- Passive integrated transponder (PIT) tags in dorsal lymph sac or intracoelomic
- Fluorescent elastomers injected into skin (safe for egg masses)
- Toe clipping - but can regenerate; perform sterilly
Which Mycobacterium is the primary cause of zoonosis from amphibians?
Mycobacterium marinum
What is diet for adult amphibians?
Carnivorous
Most require moving food
Why can’t raw meet be fed to young amphibians?
Ca deficiency or salmonella contamination
Can you feed beef muscle and organ to axolotls and mudpuppies?
Yes but need to add vitamins and minerals
What do different organs from whole vertebrate prey provide for balanced diet?
Bones = Ca, P, Mg
Liver, kidneys = vitamins
Pancreas = Zn
Thyroid = I
What to do to invertebrates to feed them to amphibians?
Dust with calcium and gut-load with vitamins/minerals
How often to feed amphibians?
2-3X per week
Why not to feed chitin-containing animals to Xenopus?
Chitin-containing animals (crickets and mealworms) can cause intestinal obstruction
How long after feeding an amphibian to avoid handling them?
Do not disrupt for 1 hr after feeding to prevent regurgitation
What is the name of the peptides secreted by X. laevis that are antibacterial, antifungal, and antiprotozoal
Magainins
What is the name of the natural opioid-like substance in skin of amphibians?
Dermorphin
What is the name of the keratinized epidermal thumb pads that male amphibians develop seasonally?
Nuptial pads (aids in amplexus aka the mating embrace)
What is name of patch on lower coelom/pelvis of amphibians and what is its purpose?
Seat patch aka drink patch
Absorb water
In amphibians the fusion of post-sacral vertebrae into an elongate bone that articulates w/ sacral vertebrae and ilium is called ___
urostyle
Which amphibians have ability to regenerate limbs, jaws and ocular tissue?
newts (Notophthalmus), axolotls (Ambystoma mexicanum)
Do X. laevis tadpoles have gills or lungs?
BOTH
They will gulp air at water surface
What is special about amphibian lungs?
Air forced in and out through buccopharyngeal floor
Lack alveoli –> very fragile
What to use for fluids for amphibians?
Use Amphibian Ringer’s solution (plasma osmolarity is 200mOsm/kg vs. mammal 290 mOsm)
What do you need to keep in mind when administering drugs into hind limbs of amphibians?
Hepatic portal vein drains blood from caudal half of body –> Drugs will pass through liver and may be metabolized before circulating to rest of body
What are the muscular structures that help pump lymph back to the heart in amphibians?
Lymph hearts
Where to perform injections into amphibians
SQ injection into dorsal lymph sacs will be directly imported into venous circulation
Amphibians excrete nitrogenous waste in what form?
Aquatic = ammonia
Terrestrial = urea
Arboreal = uric acid
What are “stitches” observed on X. laevis?
Lateral line system
How to sex X. laevis?
Females larger and have cloacal papilla
Males have nuptial pads
How does X. laevis eat?
No tongue
Feeding lowers buccopharyngeal pressure and open mouth and suctions prey in
Shred prey w/ hind claws and sweep into mouth
What nitrogenous waste form does X. laevis secrete?
Normally ammonia, but can secrete urea in times of drought
How to sex male vs female bullfrog (Rana (Lithobates) catebeianus)
Male tympanum is larger than eye; female tympanum is same diameter as eye
Do frogs have teeth? What role do they play in reproduction?
Some frogs develop teeth for male to abrade skin of females to allow intro of chin gland secretions into blood during amplexus
Which hormone is needed for metamorphosis of amphibians?
Thyroid hormone and iodine
At what age does metamorphosis and sexual maturity occur for X. laevis? How is this impacted by temperaure
2 months and 8 months
Colder temperatures slow this process
How to hormone prime X. laevis for breeding?
Inject HCG in dorsal lymph sac of both males and females (2 injections, 1-5 hrs apart)
Which suture is recommended for amphibians?
Monofilament Nylon suture is least reactive to skin
Gut and silk cause strong tissue rxn
How frequent can frogs be hormone-primed and eggs collected?
q1 month
Acceptable euthanasia methods for captive amphibians and reptiles
- Sodium pentobarbital (IV preferred, but also IC, SQ, lymph sacs)
- For poikilotherms: dissociatives (ketamine, telazol), inhaled agents, IV anesthetics (propofol, short-acting barbiturates)
- MS-222 immersion, lymph sac, coelomic cavity (first two just amphibians; last one also reptiles)
- Benzocaine hydrochloride (immersion, 7.4 or 20% topical not pure)
AC euthanasia methods for amphibians/reptiles
- Inhaled anesthetics and CO2 (breath hold –> follow with physical method)
- Penetrating captive bolt, firearm (crocodilians and large reptiles)
- Blunt force trauma
- Rapid freezing (if <4g in liquid nitrogen)
AJ euthanasia methods for amphibians/reptiles. What is the 3-step method?
- Decapitation
- Pithing
3-step:anesthetic –> decapitation –> pithing
What is the cause of red leg in amphibians?
Aeromonas hydrophila
Bacterial septicemia
Cutaneous ulcers
What causes necrotic gray foci on gills of Nectutus?
Pseudomonas
Targets gills in mudpuppy
What causes congestion and hemorrhage, panophthalmitis (conjunctival/corneal edema), meningitis, and otitis in amphibians? What is tx?
Chryseobacterium
Highly resistant to Abx and chlorine/chloramines
How to control Salmonella in amphibians?
Unlikely to eliminate
A cause of zoonosis!!
What is family/species of herpesvirus in amphibians?
What amphibian species exhibits this spontaneously?
Family: Alloherpesviridae
Lucké herpesvirus (ranid herpesvirus 1, RaHV-1) = oncogenic
RaHV-2 = isolated from tumor-bearing frogs but not oncogenic
Northern leopard frog (Rana pipiens)
Which virus causes high mortality with epizootics, often with little to no clinical signs, in amphibians?
Ranavirus (Iridovirus)
Can also appear like bacterial sepsis
In amphibians what pathogen causes dehydration, anorexia, emaciation; feces loose with blood; vomiting, find cysts in liver and kidney?
Entamoeba
Most common nematode in Xenopus? Where is organism found?
Pseudocapillaroides xenopi
Epidermis
What is the causative agent of Chytridomycosis? What is target organ?
Batrachochytrium dendrobates (Bd)
Emerging disease
Amphibians only
Bd uses keratin as substrate; restricted to superficial layers of skin
Unacceptable euthanasia methods for amphibians/reptiles?
- Hypothermia (if 4g or larger)
- Rapid freezing in liquid nitrogen (if 4g or larger)
What is the most common agent to cause chromomycosis (chronic fungal skin infxn) in amphibians? What is clinical sign?
Basidiobolus ranarum
Raised dark nodules or ulcerations
What causes metabolic bone disease in amphibians?
Fed diets low Ca or poor Ca:P
Tadpoles = require large amounts of Ca
What is sex predilection for lipid keratopathy in frogs?
FEMALES
Associated with fat mobilization related to reproduction and/or high fat diet
In amphibians what is the term for the condition involving Poor devo limbs, do not emerge from metamorphorsis properly; thin and poorly muscled; angular deformities?
Spindly leg
Which gas is the most common cause of gas bubble disease in amphibians?
Nitrogen, not oxygen
Tx: degas by aeration, increase room temp
Common cause of nasal abrasion in amphibians?
Jumping against walls and top of enclosure
Most common types of neoplasia in Xenopus?
Melanophoroma and lymphosarcoma
Most common neoplasia in Rana pipiens?
Northern leopard frog
Lucké renal carcinoma
Caused by Lucké tumor HERPESVIRUS
Which trematodes are found in the bladder of amphibians and what are the clinical signs?
Polystoma
Also Gorgodea amplicava
Asymptomatic
What order/clade is frog?
Anura
What order/clade are salamanders?
Caudata
What order/clade are Caecilians?
Gymnophiona
What are the 2 glands in amphibian skin?
Mucous (secretes mucus for protective barrier)
Granular (secretes peptides - antimicrobial etc)
What can Xenopus commonly evert during regurgitation?
STOMACH tissue
Which organs normally have black pigment?
Ovaries, liver
Main differentials for cutaneous hyperemia?
Aeromonas hydrophila
Pseudomonas
Chryseobacterium Chlamydophilosis Iridovirus (Ranavirus)
Batrochochytrium dendrobates (Chytrid)
Rana virus can be identified by eosinophilic intranuclear inclusions in _____ and basophilic intracytoplasmic inclusions in ______.
RBC
Stomach glands
Which nematode is a major parasite of X. laevis, causing desquamation and debilitation?
Pseudocapillaroides
What parasite eats the frog’s face until it dies?
Toad fly (Lucilia bufonivora)
Histolopathology for Lucke herpesvirus?
Renal adenocarcinomas
eosinophilic intranuclear inclusion bodies in kidney
clinical manifestation in wintering frogs (cooler temps) and shed during spawning
Histopathology for Iridovirus in amphibians?
Diffuse necrosis of liver and hematopoietic tissues
Which protozoal parasites are external parasites that affect the skin and gills of aquatic amphibians?
Oodinium and Trichodina
Ingestion of infected fly larvae is the likely source of which protozoal parasite in toads?
Plistophora myotropica
Which protozoal parasite infects the blood of amphibians and has an indirect life cycle?
Tryposoma
But not likely pathogenic
The three most commonly described nematodes of amphibians and the animals they affect are? Which one is found in the blood?
Pseudocapillaroides xenopi – Xenopus laevis
Rhabdias – frogs and salamanders
Foleyella – frogs **this one is found in the blood
Which nematode has a direct life cycle, lives in the epidermis, and is transmitted by ingesting sloughed skin containing eggs?
Pseudocapillaroides xenopi
Which trematode is found on the skin and gills of aquatic species of ambibians?
Gyrodactylus
Which cestode is found in the gastrointestinal tract of amphibians and causes GI obstruction?
Nematotaenia
Fungal infections most frequently identified in amphibians are?
Saprolegniasis (several fungi including Saprolegnia)
Chromomycosis (various pigmented fungi)
Phycomycosis (Basidiobolus most common)
A cottony mat of fungal hyphae covering a skin lesion is most likely caused by?
Saprolegnia
Visceral granulomas can be seen with what fungal infection?
chromomycosis (Basidiobolus)
Corneal thickening and opacity, with vacularization, superficial pigmentation, and cholesterol clefts are indicative of what disease and in what amphibian?
Lipid keratopathy seen in female frogs
Limbs that develop abnormally, do not emerge properly at metamorphosis, are thin and poorly muscled, and have angular deformities are indicative of what disease and in what amphibian?
Spindly leg seen in young frogs, particularly poison dart frogs
Gas bubble disease caused by air supersaturation of water can be seen on what part of amphibians?
Webbing of feet and skin
What structure of male frogs becomes larger and more pigmented in the breeding season?
Vocal sacs
What amphibian incubates eggs in the skin of her back?
Surinam toad
What regulates reproductive behavior in amphibians?
Arginine vasotocin (similar to arginine vasopressin but differs by 1 amino acid)
What stage of metamorphosis in the tadpole occurs when external gills are resorbed and limbs develop?
Prometamorphosis
When during metamorphosis does the tail become resorbed, forelimbs break through the operculum, and the hindlimbs become functional?
Metamorphic climax
Adult Xenopus become stressed at prolonged temperatures less than ____ and greater than ___, which can cause a decrease in oocyte quality?
14°C, 26°C
What is the life span of Xenopus in captivity?
15 years or more
To prevent fouling of water, when should static systems be changed?
After feeding
Female Xenopus should be bred a maximum of 1 time per month, what is the ideal induced breeding interval?
1-3 months
Amphibian and reptile blood should be collected in what kind of syringes?
Lithium heparin (EDTA can cause RBCs to lyse)
What vein can be used for blood collection in frogs and salamanders?
Midventral abdominal
What are the three clades in Class Amphibia?
- Gymnophipona (Caecilians)
- Caudata (salamanders)
- Anura (frogs and toads)
What is the name of the family primitive salamanders? What is the genus of the largest species?
Cryptobranchids (hellbenders)
Andrias = giant salamander
What is a defining characteristic of most families in order Caudata?
(Salamanders)
Paedomorphism (neonteny) - adults retain characteristics of larval stage
What are the primitive vs derived salamanders? Name families in each
Salamanders = order Caudata
Derived have more specialized characteristics for terrestrial life
Primitive: Sirenidae, Cryptobranchidae
Derived: Amphiuma (resemble sirens), Proteidae (mudpuppy), Ambystomatidae (axolotl), Salamandridae (lung, poison glands)
What substrates are suggested for many species of amphibians?
moistened sphagnum moss and coco fiber with a bottom layer of gravel or weight expanded clay aggregate
Recommended temperature for tropical vs temperate species of amphibians
Tropical species 21-29C, 70-85F
Temperate species 18-22C, 65-72F
(Axolotl 21-22)
What species of toad requires eye protection because pressing on the parotid gland causes an ejection of a toxin?
Rhinella marina (cane toad)
In many frog species, the trachea is short, and _______ occurs close to the glottis; this anatomic feature must be taken into account when performing endotracheal intubation.
Bifurcation
How many heart chambers do larval and adult amphibians have?
Larva have 2 chambers like fish
Adults have 3 chambers (two atria, one ventricle)
Salamander and frogs have a ______ kidney and lack the ability to ______.
Opisthonephric kidney
Lack ability to concentrate urine in excess of plasma
In amphibians, neuromasts detect changes in ___ and ___, and function in ______.
Water pressure and currents
To detect prey (adult amphibians are carnivorous)
Amphibians can detect higher-frequency sound transmitted through the air to the ____, but low-frequency vibration is transmitted through the ____ and the ____.
Higher frequency directly through tympanic membrane
Lower frequency relayed from the forelimbs and the cranium to the ear
How to determine age of Xenopus?
Count layers in bone
Do adult amphibians eat larvae?
Yes; will even cannibalize larvae of their own species
What clade has turtles, crocodiles, and birds?
Archosauria
What clade has lizards, snakes, amphibians?
Lepidosauria
What family contains turtles?
Chelonia
What family contains Caimans, crocodiles, alligators?
Crocodylidae
What are anapsid vs diapsid reptiles?
Anapsid = no hole (no temporal fenestrations in skull) –> historically turtles (but now considered diapsids)
Diapsid –> lizards, snakes
Which reptile is used to study anoxia tolerance and mechanisms of neuroglobin?
Trachemys scripta elegans (Red eared sliders)
Why you can’t use corncob or cat litter as substrate for reptiles?
can ingest and cause impaction, desiccate young animals
Are aquatic reptiles or amphibians more tolerant of chlorinated water?
Aquatic reptiles
amphibians will die
What type of UV is required by many reptiles?
Many require UVB spectrum for endogenous Vit D3 production (290-300 nm)
if not (or if low Ca or inappropriate Ca:P ratio), develop metabolic disease
How far from animal to place UV light for reptiles?
How often to change bulb?
24 inches away
Be sure cage lid does not block UV light
Change bulb every 6 months.
ID methods for reptiles
Paint
Shell notching
Scale clipping
Toe clipping (controversial, can affect ability to grip)
External tags
Implanted transponders.
**If extending clipping/notching into dermal bone/tissues, need appropriate technique and analgesia.
Length of quarantine recommended for snakes
90 days
What is most common zoonosis from reptiles?
Salmonella, as reptile carry asymptomatically and can shed if stressed. If pregnant or child <5 years old should not hold reptile.
What is an important zoonosis from AQUATIC reptiles?
Aquatic reptiles can carry Mycobacteria sp and Edwardsiella tarda; humans infected via contaminated water.
What is the term for shedding in reptiles?
Ecdysis
What are the 3 specialized epidermal layers in reptiles?
Most superficial: Oberhäutchen (thin layer keratinized epidermal cells)
Next outer layer: beta keratin (hard)
Inner layer: alpha keratin (elastic)
Normal skin found between scales
Describe ecdysis in snakes and lizards.
- Takes 1-2 weeks to form extra epidermal layer
- Lymph accumulates between layers (= opaque), then resolves **more defensive if handling during this; they cannot see
- 3-4 days later shed
Describe epidermal growth in turtles and crocodiles (i.e. do not shed).
Crocs and turtles have continual epidermal growth with osteoderms
What glands do turtles have?
- Rathke’s glands in inguinal/axillary area
- Mental glands in mandibular area
What glands do crocs have?
Cloacal glands
What special gland do desert and marine reptiles have?
Salt gland to excrete excess salt
How many ribs do crocodiles have and what special structure is associated?
8 true ribs, each has an additional floating dermal bone rib associated w/ it called gastralia (dermal bones) that connects sternum to pelvic bones
What do snakes not have that allows them to swallow large prey?
mandibular symphysis
For boas/pythons what sticks out on either side of vent and is used for courtship?
Spurs (vestigial hind limbs)
What are dorsal shell and ventral bone of turtles called?
Carapace
Plastron
What do lizard tails contain for defense?
‘fracture planes’ allow autotomy (tail to separate as defense mechanism), cartilage, not bone, grows back
what do Crocs have to allow them to hold large prey while submerged without choking/drowning
basihyal valve
Describe snake lower respiratory tract
Incomplete tracheal rings
Faveoli to increase surface area
Air sac at posterior aspect of lung
How many chambers does reptile heart have? Who is the exception?
3 chambers (2 atria, 1 ventricle)
Except crocodile has 4 chambers
What structure provides connection between aortic arches to shunt blood to cephalic and coronary circulations during anoxic events like diving?
Foramen of Panizza
While diving, do not need blood to go from right aortic arch to lungs –> shunt to left aortic arch to rest of body
What vessel do lizards have under abdominal wall, which should be avoided when making incisions!
midventral abdominal vein
What do vipers and elapids have in common and what is distinct?
Both have true venom glands
Vipers retractable; elapids fixed
What gland do colubrids have?
Duvernoy’s gland
Not a true venom gland
Do Gila monsters (Heloderma suspectum) and beaded lizards (Heloderma horridum) have venom?
Yes; through mandibular salivary glands
Increased by CHEWING
What is gelatinous secretion around cloaca after mating and what is differential diagnosis?
In some snakes/iguanids, sexually dimorphic kidneys w/ sex segments that form copulatory plugs
Do NOT mistake for gout, though can look similar
What is seen in the kidneys of reproductively active male snakes?
Sexual segments that are grossly pale in color; histologically contain eosinophilic refractile granules
What is nitrogenous waste for reptiles?
Aquatic species excrete ammonia; semiaquatic secrete urea; terrestrial excrete uric acid
What is renal portal system?
drains blood from caudal 1/2 of body directly thru kidneys, may also be diverted to liver in some instances
Imp. for routes of admin of drugs undergo renal or hepatic metabolism
What are fused clear lids in snakes and geckos?
spectacles
they do not blink
What do some lizards, including green iguanas, blue-tongue lizards, and tuataras have to aid in vision?
parietal/third eye w photoreceptors for low light detection
green iguana = Iguana iguana
What structure picks up infrared heat for prey targeting in some snakes?
Loreal pit
What do reptiles and amphibians have in common with birds?
Nucleated RBCs
Which animals have heterophils (analogous to neutrophils)
birds, reptiles, amphibians, rabbits, fish, GP, hamsters
What is name for snake monocytes?
azurophils
How often to feed snakes and turtles?
Snakes: q1-4 weeks
Turtles: every day for smaller, 2-3 times per week for larger
How to sex turtles
Male: concave plastron, long tail, and cloaca further down the tail
Female: straight or slightly convex plastron, short stubby tail, and cloaca right up next to the plastron
Term for male snake and lizard sex organ
Hemipenes
Which reptile is all-female and exhibits parthenogenesis?
Whiptail lizards (Aspidoscelis uniparens)
What temperature produces males vs females in alligators?
Warm temp: male
Cool temp: female
(opposite in zebrafish)
Blood collection sites in reptiles?
Ventral tail vein is a common location
Snakes can be bled via cardiocentesis
Lizards from ventral midline abdominal vein
Where to give injections in red-eared sliders (Trachemys scripta elegans)?
have hepatic first past metabolism if injection given in caudal part of the body or the abdominal vein
Inject in front limb to decr 1st pass
Where to give injections in reptiles?
Drugs metabolized by kidney or liver should be injected into the epaxial muscles in cranial half of the body in snakes or the muscles of the front legs in chelonians, lizards, and crocs
Treatment for GI stasis in reptiles (after ruling out obstruction)?
Can use cisapride, erythromycin, metoclopramide to promote gastric emptying
Which bacteria in reptiles produce toxins and cause cell death?
E. coli, Clostridiuum, K. oxytoca, Vibrio, and Helicobacter
Are bacterial infections in reptiles usually primary or secondary?
Secondary
Why does Mycoplasma cause high M&M in turtles and tortoises?
Have genes incl hyaluronidase, sialidases, and mucinases that allows to spread systemically
Which bacteria cause URT infection in reptiles?
Pseudomonas, Aeromonas, and Klebsiella spp.
Which bacterium causes SQ abscesses in reptiles?
Serratia
Which bacterium causes aural abscesses in turtles?
Morganella morganii
Which bacteria causes chronic resp dysfunction – clear to purulent nasal d/c, swollen eyelids, occlusion of upper airways (advanced cases)?
Mycoplasma
M. iguana and insons – healthy green iguanas no CS
M. agassizii and testiduneum – respiratory dz in snakes, tortoises, and turtles
M. alligatoris and crocoduli – severe lethal dz in alligators, caimans, and crocs
**Zoonotic
Which bacteria in reptiles causes serosanguious fluid in trachea and white/gray nodules in lungs + darkened mucosa w/ petechial and ecchymosis in GI + bone and joint abnormalities? What would you see on histo? Which reptile most susceptible?
Mycobacterium
Histo shows clusters of macrophage containing IC acid fast bacilli making caseating granuloma
Chelonians
You see a turtle with respiratory signs and fibropapillomas. What is etiology? What type of chelonian is highly susceptible and what is observed on pathology?
Herpesvirus
Marine turtle e.g. Chelonia mydas (Green sea turtle). Hepatomegaly and pulmonary edema.
But also can affect snake (decreased venom production) and lizards (stomatitis, papillomas)
Ddx for CNS signs in reptiles?
- Adenovirus (genus Atadenovirus)
- Inclusion body disease (Arenavirus)
- Reovirus
- Mycoplasma
- Mycobacteria
- Paramyxovirus
- Fungal
- Toxin
Primary differential for reptile with skin lesions (predominantly on head) and pruritus? What is seen on histo? What disinfectant to use?
Poxvirus
eosinophilic ICIB and ballooning epidermal cells
Poxvirus is resistant to many disinfectants (low lipid content), but 1% KOH, steam and 2% NaOH effective
What is observed on pathology for adenovirus?
hepatic necrosis, INIB
Which 3 systems are affected by reovirus in reptiles?
CNS, respiratory, GI
Which reptile shows high M&M with ranavirus? What is the family for ranavirus? What is the reservoir? What is special about replication of this virus?
Chelonians, especially young/immunosuppressed
Iridoviridae
Arthropods (crickets)
In cytoplasm and nucleus (2 stages)
Clinical signs and pathology for ranavirus
CS: UD w/ hyperkeratosis, oculonasal d/c, conjunctivitis, diphtheroid-necrotic stomatitis, lethargy, anorexia, SQ cervical edema and “redneck dz”, 2° bacterial infx
Path: necrosis of pharyngeal submucosa, hepatitis, pneumonia, enteritis, splenitis, UD, vasculitis/thrombosis
What virus causes small white proliferations on turtles and black proliferations on snakes? What type of inclusions?
Papillomavirus
INIB and IC vacuoles in epithelial cells
What is the most clinically significant amoeba in reptiles? Which reptiles have high mortality?
Entamoeba invadens
Snakes/lizards
What species of Cryptosporidium affect snakes, lizards, and turtles and which part of GIT? Tx to decrease shedding?
Snakes: C. serpentine (severe dz – usually fatal)
In gastric glands –> gastric hypertrophy –> chronic regurg
Lizards: C. varanii
In SI –> diarrhea
Turtles: C. varanii
In SI –> cloacal prolapse
Unlike mammals, not self-limiting
tx w/ hyperimmune bovine colostrum not successful in eliminating organism just decreasing shedding
What is the snake hookworm?
Kalicephalus
What is reptile roundworm/Ascarid? How is it transmitted?
Cyrtosomum penneri
venereal transmission NOT fecal-oral
Which microfilaria cause dermatitis in pythons? Where is the organism found?
Macdonaldius oschei
Mesenteric veins — associated granulomatous response
Ivermectin is toxic in which type of reptile?
Chelonians and skinks
What is tongue worm of reptiles? What is life cycle
Pentastomes
IH = mammals, fish, insects🡪 IH ingests eggs in feces or sputum of reptile🡪 larvae encyst in viscera🡪 IH eaten by reptiles w/ nymphs🡪 migrate from GIT to lung/air sac or SQ tissue🡪 bore thru skin, coughed up, swallowed🡪 feces
Which species of mites affect snakes and lizards?
Ophionyssus natricis – common snakes
Ophionyssus acertinus – common in lizards
Can transmit worms
Ddx cranial and facial deformities in lizards
Metabolic bone disease - caused by calcium deficient diet, inappropriate Ca:P ratio, lack of UVB
good prognosis
Ddx for hyperkeratosis or squamous metaplasia of resp, ocular, GIT in chelonian?
Vitamin A deficiency
Aural abscesses
What type of crystals accumulate in gout? What is treatment?
Urate
BUN/creatinine not useful in reptiles
tx:
-Allopurinol – lowers serum uric acid levels
-Probenecid – promotes urate excretion
-Anti-inflammatories/steroids – arthritis
Types of dystocia in reptiles
Obstructive
Non-obstructive (caused by dehydration, malnutrition, lack of appropriate substrate for chelonians and digging site for lizards): especially in chelonians and lizards eg green iguana
What are causes and how to treat dysecdysis
causes: improper temp/RH/nutr, overcrowding, improper photoperiods
tx: Soak in warm water and loosen skin or retained spectacles gently
Suture tail injury in lizards?
No - will prevent regeneration
What type of neoplasia do chelonians, snakes, and lizards get
Chelonians
1. Integument fibromas, fibropapillomas
2. Carcinomas in GIT
3. Adenoma of endocrine system
Snakes
1. SCC
2. Fibrosarcoma
3. Lymphoma
Lizards
1. Lymphoma and adenocarcinoma of kidney/GIT
2. Fibrosarc of integument
Which reptiles are commonly used to teach anatomy and physiology?
Chrysemys picta (painted turtle) and Trachemys scripta elegans (red-eared slider)
Which reptiles are commonly used to study endocrinology and behavior?
Green anole (Anolis carolinensis)
What class are reptiles in? What distinguishes them from other vertebrates?
Reptilia
first vertebrates to evolve an amniotic, shelled egg; therefore, they no longer require an aquatic environment for reproduction
What are the clades under diapsids?
Archosauria (turtles, crocodilians, birds)
Lepidosaurians (squamates ie lizards/snakes, tuataras, amphisbaenians)
Are reptiles more closely related to amphibians or birds?
Birds
Furthermore, snakes and amphisbaenians
evolved from lizards, making lizards ____.
paraphyletic (the one in the group that does not have a common ancestor with the others)
Chelonians (turtles and tortoises) are divided into
two broad taxonomic groups:
based on the method of
head retraction
- Pleurodira = side-neck turtles; withdraw
the head and neck and fold it onto the shoulder e.g. Chelus fimbriatus, the mata mata - Cryptodira = withdraw the neck into the shell in a vertical, S-shaped fashion
What family contains the sea turtles?
Cheloniidae and Dermochelyidae
What family contains soft-shelled turtles?
Trionychidae
What family contains mud and musk turtles?
Kinosternidae
What family contains snapping turtles?
Chelydridae
Which crocodilians have been most commonly used in research?
The common caiman
(Caiman crocodilus) and American alligator (Alligator
mississippiensis)
Which snake family has members whose venom is primarily neurotoxic?
Elapidae
What are crocodilians used for in research? (Name 3)
- Neuroanatomical /neurophysiological research
- Development of artificial blood
- Transmyocardial perfusion techniques
Softshell and leatherback sea turtles have (α-keratin, β-keratin) covering their shells
a-keratin (soft, elastic)
The glottis of reptiles is easy to visualize. It lies in the ______ part of the mouth in snakes and many lizards and behind the base of the _______ in turtles and crocodilians.
cranial, tongue
Many snakes have an elongate _____ lung and either no or a small vestigial ______ lung.
right
left
The lungs of snakes and many lizards end in extensive ______.
air sacs
- Type of lung in turtles and crocodilians
- In turtle, the movement of the _______ and ______ cause air to be forced in and out of the lungs.
- Crocodilians have a muscular ______ that functions like a mammalian diaphragm.
compartmentalized
head, limbs
septum
What is the only type of snake with vocal cords?
the pine snake, Pituophis melanoleucus
Which reptile’s stomach often contains gastroliths to aid in digestion?
Crocodile
What type of kidney do adult reptiles have?
Metanephric (vs fish/amphibians have opisthonephric, an extention of mesonephric)
What animals have Harderian glands?
Amphibians, reptiles, birds, rodents, rabbits
Why do prey food items need to be thawed?
avoid putrefaction (rotting) of food in the stomach
What is different about the forelegs of male red-eared sliders?
males have elongated claws on their forelegs to stroke the sides of female’s head during courtship
What is the difference between the tails of male and female snakes?
male snakes have longer, thicker, more gradually tapering tail
Which group of reptiles have a single, fleshy penis?
Turtles, crocodiles
How to differentiate male and female lizards?
male lizards have a large row of femoral pores on the inside of the hindlegs which are scent glands (females smaller or absent)
The total blood volume of reptiles ranges between _____ and _____% total body weight. ___% of the total blood volume can safely be collected from a reptile.
5 and 8%, 10%
Four sites for blood collection in a turtle or tortoise?
Ventral tail vein, jugular vein, brachial plexus, occipital sinus
In Reptiles, in order to obtain a fresh fecal sample, a ____ should be performed.
colonic wash
What additional radiographic view is recommended for evaluation of the respiratory tract in chelonians?
The cranio-caudal view along with standard views
For Xenopus which digits have claws?
First three digits on hind limb have claws
