Intro to Chelonians Flashcards
(62 cards)
1
Q
What is a chelonian?
A
- Turtle - aquatic (marine)
- Tortoise - terrestrial
- Terrapin - aquatic (freshwater)
2
Q
What is a chelonian’s metabolism like?
A
- Slow - 1/5 - 1/7 of mammalian metabolism
- Varies with:
- species
- metabolic state
- temperature
- immune status
- general husbandry conditions
- Anaerobic metabolism:
- switch to anaerobosis with vigorous activities
- Increased lactate production
3
Q
Define Poikilothermia
A
Inability to regulate core body temperature
4
Q
Define Ectothermia
A
regulation of body temperature depends on external sources
5
Q
What are the pros and cons of being Poikilothermic/Ectothermic
A
- Pros - do not waste energy for thermogenesis
- Cons:
- activities are limited by ambient temperature
- Limited aerobic capacity
- Brumation
6
Q
What is the optimum temperature zone for chelonians?
A
7
Q
What is the chelonian shell?
A
- Unique to this order of reptiles
- Flat, plate-like bones that surround spongy, cancellous tissue
- Dermal bone
- Fused ribs, vertebrae and some osteoderms
- Carapace
- Plastron
- Bridges
- Pectoral and pelvic girdle within the carapace (rib cage)
- Shell (dermal bone) covered by epidermal tissue ⇢ flexible, keratinized plates (Scutes)
- Scutes and the bones are staggered so the horny plate sulci do not sit between the bony plate surures
- Scute and bony plate terminology is slightly different and is based upon anatomical location
8
Q
what coelomic cavities do chelonian have?
A
- Pleural cavity
- Peritoneal cavity
- Separated by post-pulmonary septum
9
Q
What type of GI system do chelonians have
A
- Varies depending on diet
- long with 1 cecum in herbivorous species, large colon
- Cloaca
- combined body system’s outlet
10
Q
What type of respiratory system does a chelonian have?
A
- Trachea
- complete tracheal rings
- Tracheal bifurcation very cranial in chelonians
- Larynx similar to birds - No epiglottis
- Lungs:
- Multicameral (complex, many-chambered)
- Gas exchange surface includes ediculae and gaveolae (larger than alveolae)
- Breathe with their legs
11
Q
What type of Cardiovascular system do chelonians have?
A
- 3 chambered heart
- Incomplete ventricular septum
- muscular ridge that minimizes mixing of oxygenated and deoxygenated blood
- well0developed in some chelonians
- muscular ridge that minimizes mixing of oxygenated and deoxygenated blood
- Pathway of blood:
- Precaval + Postcaval + hepatic veins ⇢ sinus venosus (unique to reptiles, dorsal to right atrium)
- Ventricle divided into 3 subchambers
- Cavum pulmonale (ventral) - extends cranially into the pulmonary artery ⇢ deoxygenated blood to lungs
- Cavum arteriosum (dorsal)
- Cavum venosum (dorsal - extends to the aortic arch ⇢ carriers oxygenated blood systemically
12
Q
what is the renal system of chelonians like
A
- most are uricotelic (secrete uric acid as end product)
- some (typically aquatic) secrete a significant amount of urea
- Reptilian nephrons
- loopless = do not concentrate water
- have a large, bilobed urinary bladder
13
Q
what is the repro system of chlonians like?
A
- intracoelomic gonads
- phallus
- Sexual organ
- Not an outlet for Urine
- Can be “exhibited’ - not the same thing as a prolapse
- Prolapse can occur and can result from a variety of disease conditions
- oviparous
- typically do not incubate eggs
- sex ratio often determined by temperature
14
Q
How are male and female chelonians sexed?
A
- Males:
- Concave plastron
- Long Front toenails
- Vent extends well beyond margins of shell
- Eye color (box turtles -red)
- longer tail
- Typically smaller
- Anal scutes V-shaped
- Females:
- Flat plastron
- Short toenails
- Vent does not extend beyond margins of shells
- Eye color (box turtles - brown)
- Shorter tail
- Typically larger
- Anal scutes U-shaped
15
Q
How should chelonians be handled?
A
- Always get back up for large and potentially dangerous reptiles
- If unsure of the species or temperament of the animal, wear gloves
- Wear gloves or wash hands thoroughly after handling
- zoonotic risk with salmonella
- Hold across the middle of the shell or the edge of the carapace and plastron with both hands
- Can bite and scratch with their beaks and toenails (turtle > tortoises)
- Will retract head and limbs making examination difficult
16
Q
What is the equipment needed for a PE of a chelonian
A
- Doppler (HR)
- Ophthalmology instruments - direct ophthalmoscope
- Credit card/spatula or mouth speculum (to examine oral cavity)
17
Q
How can HR and RR be obtained on chelonians?
A
- Reptiles can hold their breath for long periods of time (sometimes several minutes)
- HR - cannot auscultate most of the time ⇢ use doppler
- Place on neck over the carotid artery or in the thoracic inlet
18
Q
How are chelonian bodies scored?
A
- Range 1 to 9
- Look at:
- palpability of ribs
- pectoral/pelvic girdles
- girth of tail
- muscle mass of forelimbs and hind limbs
19
Q
How is the coelomic cavity palpated
A
- One or two fingers placed in the inguinal area between the hindlimbs and shell
- Feel for cystic calculi, foreign bodies, neoplasia, potential eggs
20
Q
Where can blood be collected from chelonians?
A
- Jugular vein
- brachial vein
- dorsal coccygeal vein
- subcarapacial plexus
21
Q
What unique cells appear on a chelonian CBC?
A
- Heterophil
- function similar to neutrophil, lacks the enzyme myeloperoxidase
- purulent material is thick and not liquified
- function similar to neutrophil, lacks the enzyme myeloperoxidase
- Azurophil
- Behaves like a heterophil in snakes
- Behaves like a monocyte in all other reptiles
- Appearance of cells varies by species
22
Q
What is different about the Biochemistry profile of chelonians?
A
- Lymph dilution is a concern - any sample with clear fluid or a watery appearance may have lymph dilution (or it may appear grossly normal)
- Can reduce all parameters, but most severely affected are total protein and potassium
- Effect of sex:
- females - higher cholesterol total calcium, total protein, albumin
- Seasonal effects - brumation
23
Q
What collection tubes should be used for chelonian blood
A
- some species will hemolyze in EDTA (purple tube)
- Blood should preferably be put in heparin (green tube)
24
Q
Where should intramuscular injections be given in chelonians?
A
- Tail and rear limbs avoided because of the presence of a renal portal system ⇢ do NOT use caudal half of the body for infections
- drugs given in the caudal portion will enter into the ventral abdominal veins and pass through the hepatic vein first. So will undergo a hepatic first-pass effect
- Blood from the hindlimbs/tail can directly reach the kidneys, and nephrotoxic drugs may result in severe renal tissue damage. Or if renally excreted may result in ineffective levels of drugs (Renal first-pass effect)
- Locations:
- Upper arm (deltoid, triceps)
- Forearm (biceps)
- pectorals
25
Where should subcutaneous injections be given in chelonians?
* Axillary and inguinal spaces
* Technique - insert needle parallel to body wall in between scales
26
What other routes can be used for drug administration in chelonians?
* Intracoelomic (not recommended)
* Oral
* Intravenous
* Intraosseous - humerus, femur, gular, bridge
* Cloacal
27
How can radiographs be taken of chelonians?
* Small patients - use dental radiographs
* Positioning:
* Dorsoventral
* Lateral (horizontal beam)
* Craniocaudal (horizontal beam)
28
What other diagnostic imaging can be done on chelonians?
* Ultrasound
* can be limited (thick shell)
* 2 axillary windows
* 2 prefemoral fossa windows (inguinal)
* CT
* extremely helpful
* creates a 3D picture and remove challenges associated with imaging animals with large boney shells
29
What Husbandry-Associated Diseases exist in Chelonians
* Hypovitaminosis D
* Metabolic bone disease
* Beak deformities (acquired and congenital)
* Vitamin A deficiency
* Cloacal prolapse
* Urolithiasis
* Reproductive disease:
* Egg-binding/dystocia
* Follicular stasis
30
What are the infectious diseases of chelonians
* Salmonella spp
* Mycobacteriosis
* Generalized abscesses
* Testudinid Herpesvirus
* Other herpesviruses too
* Ranavirus
* Mycoplasmosis
* Ulcerative shell disease
* Intranuclear Coccidiosis of Testudines (TINC)
*
31
What are the nutritional requirements of chelonians?
* Range from herbivorous to omnivorous to carnivorous
* Herbivores
* Wide variety of greens
* certain veges
* very small amounts of fruits
32
What is Hypovitaminosis D?
* Vitamin D required through dietary intake and through synthesis in the skin via UV
* Necessary for intestinal absorption of calcium
* Hypovitaminosis D ⇢ calcium deficiency
* result in metabolic bone disease
33
How is Metabolic bone disease diagnosed
* Solid history (poor diet, lack of UV)
* Clinical presentation
* Bloodwork - inverse Ca:P ratio, low tCa (often normal) low iCa
* Imaging - decreased bone density
34
What are the clinical signs of metabolic bone disease in chelonians
* Tremors
* weakness
* seizures when severe
* anorexia/hyporexia
* soft or deformed shell
* reluctance to move
35
How is Metabolic bone disease treated/prevented
* Improve husbandry and environmental conditions
* Temperature, UV, humidity
* Expose to unfiltered sunlight
* screens - must be large enough to allow light through
* No glass - block UV
* Artificial light with UVB - Must replace q6 months (UV portion burns out)
* Calcium supplementation
* high quality diet
* Calcium supplementation - injectable, oral
* Supportive care - fluids, heat, feeding
36
What is Vitamin A deficiency like in Chelonians? diagnostics? treatment?
* Squamous metaplasia of epithelial surfaces
* swollen conjunctiva very common presentation
* Loss of protective respiratory ciliary mechanism
* Secondary respiratory infections
* ocular and nasal discharge
* Buoyancy issues
* May predispose to inner and middle ear infections ⇢ aural infections
* Wild turtles - Potentially organophosphate (OP) toxicity
* Diagnosis:
* history, clinical signs, postmortem findings
* Treatment:
* oral/parenteral Vit A
* Ophthalmic ointments as needed
* Antibiotics (secondary infections)
* Correction of diet
* Supportive care - fluids, heat, feeding
* Sx for aural abscesses
37
What is cloacal prolapse in chelonians? DDx?
* Consider it could also be phallus, bladder, intestines, oviduct
* Cause not always clear (Differentials):
* Urolithiasis
* Dystocia
* Endoparasitism
* Neoplasia
* Ca-deficiency
* Enteritis
* Goal: ID what anatomical structure is involved
* may require amputation
38
What is urolithiasis of chelonians? Dx? treatment?
* Very common in desert species
* Often non-specific signs in addition to hematuria, straining, cloacal-prolapse
* may be an incidental finding
* Cause: chronic dehydration and urate sediment concentration (100% urate)
* Dx: Imaging (radiographs, CT)
* Tx: Surgery
* prefemoral approach
* plastonotomy
* Lithotripsy
39
What reproductive diseases are in chelonians?
* Egg-binding/dystocia
* Follicular stasis
* Etiology:
* Likely multifactorial
* Poor diet, low humidity, poor cage design (inappropriate or lack of substrate, lack of shelter, inappropriate lighting/timing of lights)
* Dx: Imaging (radiology, CT)
* Tx:
* correct husbandry
* substrate, temperature, calcium in diet, appropriate humidity, nesting area
* Surgery
40
What Trauma is commonly seen in chelonians? Treatment?
* Shell Fractures
* commonly caused by HBC
* Assessment:
* location
* simple or compound
* Visceral involvement
* Aquatic or terrestrial species
* Wild chelonian - potential release?
* Treatment:
* Clean fracture site
* Stabilize and cover
* Mesh
* epoxy glue
* dental acrylic
* screws
* wire
* plates
* Antibiotic
* Analgesia
* Surgical stabilization
* Feeding
* Dry docking?
* Recovery can take 6-12+mo
41
What causes infectious diseases in chelonians?
* Suboptimal environment and inappropriate husbandry can predispose or precipitate infectious disease
* Opportunistic pathogens and environmental pathogens commonly implicated
* Primary pathogens exist even in environments with optimal husbandry
42
Why is it a concern for Chelonians to carry *Salmonella spp*
* Carried asymptomatically by most reptiles in GI flora
* Zoonotic disease
* children \<5yo and immunocompromised individuals are advised against reptile interactions
* Symptomatic disease syndromes seen in reptiles:
* Abscesses
* Osteomyelitis
* Snakes
* vertebral osteopathy
* Necrotizing gastroenteritis
* Common spp in reptiles:
* All taxa
* *Salmonella enterica* (and subsp. *enterica)*
43
How is *Salmonella* carrier status assessed in chelonians
* Requires 5 cultures over 30 days
* shedding is intermittent
* Cannot declare that a reptile is salmonella-free
* Cannot be deemed free by treating with antibiotics
* Resistance develops
* Do NOT treat carriers - creates more zoonotic concern
44
What is Mycobacteriosis in chelonians?
* Most common in aquatic chelonians, any species can be affected
* Main features
* Disease most commonly granulomatous
* Detection via acid fast in an area of granulomatous inflammation = highly suspicious for infection
* \>100 mycobacteria/ml of tissue necessary for visualization so negative does not = definitive negative
* Slow growing - culture most successful from unfixed biopsy sample
* Treatment:
* Difficult, not often recommended due to zoonotic concern
* euthanasia if speciation reveals an organism of significant zoonotic concerns
* If attempted - multimodal for 6mo-1yr ⇢ recheck biopsy and hematology
* Then recheck CBC q3mo for several years for leukocytosis (suspected recurrence)
* No proven or approved treatments in reptiles
45
What mycobacterium species are common to chelonians?
* *M. chelonae*
* *M. szulgai*
* *M. marinum*
* *M. foruitum*
* *M. ulcerans*
* *M. leprae*
* *M. haemophilum*
* *M. avium*
* *M. kansasii*
* *M. terrae*
* *M. leptaemurium*
46
What are generalized abscesses in chelonians? Dx? Tx?
* Most external ‘masses’ are actually abscesses
* usually inspissated and surrounded by a fibrous capsule
* often impenetrable to drug therapy
* Hematogenous spread possible
* Predisposing factor: hypovitaminosis A
* Squamous metaplasia ⇢ periocular, perioral, glossal, and oral abscesses
* Dx: Imaging, culture and sensitivity
* Tx:
* Ideally remove entire capsule
* Marsupialization with second intention healing and daily lavage
* Recurrence common
* Husbandry correction may be necessary
47
What is Testudinind Herpesvirus? Clinical signs? Dx? Tx?
* TeHV3 most widespread and pathogenic of the herpesviruses
* Causes substantial illness in Hermann's tortoises and Russian tortoises
* Clinical Signs:
* Stomatitis
* Diphtheritic plaques in the mouth (rarely esophagus)
* Rhinitis - clear and serous progressing to thick purulent discharge
* Conjunctivitis
* Oral discharge
* Occasionally CNS signs with head tilt and circing
* Weight loss, cachexia, difficulty breathing
* Latent infection - all survivors chronically infected
* Dx:
* Serologic tests - serum neutralization, ELISA, indirect immunoperoxidase
* more useful in chronic infections
* Molecular methods: PCR, RT-PCR
* Impression smears
* Virus isolation
* Histopathology: eosinophilic intranuclear inclusion bodies
* Tx:
* Acyclovir or ganciclovir
* Supportive care
48
What other herpesviruses exist in sea turtles
* Gray patch disease
* Fibropapillomatosis
* Lung, eye, trachea disease (LETD) virus
* Loggerhead genital-respiratory virus (LGRV)
* Loggerhead orocutaneous herpesvirus (LOCV)
49
What other herpesviruses exist in freshwater turtles
Hepatitis
50
What is Ranavirus in Chelonians? Signs? Dx? Tx?
* Causes viral disease in many ectothermic animals
* Fish
* Ambhibians
* Reptiles
* Chelonians (freshwater turtles, boxturtels, tortoises)
* Clinical signs:
* Subcutaneous edema ("red-neck disease")
* Nasal discharge
* Conjunctivitis and ocular discharge
* Stomatitis
* Systemic disease
* Death
* High mortality Rate
* DX:
* CBC - Anemia, intracytoplasmic inclusions
* ELISA
* PCR, real-time PCR
* Virus isolation
* EM
* TX: acyclovir
51
What is mycoplasmosis like in Chelonians?
* Mostly in _wild_ North American tortoises
* Several spp. (*Mycoplasma agassizii, M. Testudineum)*
* Transmitted through direct contact most commonly
* Subclinically affected tortoises can act as source for naïve animals
52
Clinical signs of mycoplasmosis?
* Rhinitis and nasal dishcarge
* Conjunctivitis and ocular discharge
* Palpebral edema
* Conjunctival hyperemia
* Chronic infections - grooves from nares, depigmentation around nares
53
How is mycoplasmosis diagnosed in chelonians?
* Culture
* PCR (genus specific) - nasal swab or flush
* ELISA - Ab 6-8wks post infection ; passive transfer demonstrated
* Paired titers
54
What is the treatment/prognosis of mycoplasmosis in chelonians
* Tx:
* Persisten infection and shedding
* no guidelines for treatment and release
* Enrofloxacin, clarithromycin, tulathromycin
* Prognosis:
* Acute mortality rare
* Some clear infection
* Most deveop chronic infections
* persistence in nasal epithelium with mucosal damage ⇢ ⇡ Susceptibility to secondary infections
* Death due to severe debilitation
55
What causes Ulcerative shell disease
* “SCUD” septicemic cutaneous ulcerative disease
* “Shell rot”
* Variety of etiological agents contribute:
* *Citrobacter freundii*
* *Aeromonas hydrophila*
* *Morganella morganii*
* *Clostridium spp*
* *Saprophytic fungi*
* Other factors:
* suboptimal husbandry
* Poor water quality
56
What are teh clinical signs of Ulcerative shell disease
* Pitted scutes that may slough and reveal underlying hyperemia and purulent discharge
* Anorexia, lethargy
* Petechial hemorrhages of the shell and skin
* Liver necrosis and abscessation
57
How is ulcerative shell disease diagnosed? Tx?
* Cytology and culture and sensitivity (bacterial and fungal causes)
* Tx:
* Shell lesion debridement
* Dry docking for aquatic species
* Systemic antibiotitcs
* Possibly ntifungals
* Husbandry corrections
* Analgesia
58
What is Intranuclear Coccidiosis of Testudines (TINC)?
* Systemic disease involving multiple organs
* highest numbers of organisms in kidneys and pancreas
* Can either rapidly progress to death or see improvement with months of anticoccidial therapy and improved husbandry
* Contributing factors:
* Stress
* Thermoregulatory challenges
* Carrier animals with recrudescence of clinical signs possible
59
Clinical signs of TINC
* Disseminates systemically - clinical signs vary
* Mucosal changes: conjunctival or nasal erythema or discharge
* Ulceration of cloacal mucosa
* Subcutaneous edema
* Anorexia and lethargy
* Abnormal diurnal patterns
* Increased respiratory effort and open mouth breathing
* Weight loss (or gain from ascites and urine retention)
60
How is TINC diagnosed
* Cytology of nasal discharge
* Biopsy and histology of affected tissues
* Fecal floatation
* Quantitative PCR on swabs from conjunctiva, oral and choanal mucosa, and cloaca
61
How is TINC treated?
* Correct husbandry deficiencies
* prompt removal of feces
* minimize stress
* appropriate preferred optimal temperature zone critical
* Isolate affected individuals
* Fluid therapy as indicated
* Broad spectrum anthelmintic, antiprotozoal and antibiotic therapy
* Toltrazuril
* Ponasuril
62
What is the prognosis of TINC
* Death common
* Treatment may eliminate organism, but histologically often com across tissue slcerosis (= long term organ effects)
