Intro to Chelonians Flashcards
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
Q
Where should subcutaneous injections be given in chelonians?
A
- Axillary and inguinal spaces
- Technique - insert needle parallel to body wall in between scales
26
Q
What other routes can be used for drug administration in chelonians?
A
- Intracoelomic (not recommended)
- Oral
- Intravenous
- Intraosseous - humerus, femur, gular, bridge
- Cloacal
27
Q
How can radiographs be taken of chelonians?
A
- Small patients - use dental radiographs
- Positioning:
- Dorsoventral
- Lateral (horizontal beam)
- Craniocaudal (horizontal beam)
28
Q
What other diagnostic imaging can be done on chelonians?
A
- 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
Q
What Husbandry-Associated Diseases exist in Chelonians
A
- Hypovitaminosis D
- Metabolic bone disease
- Beak deformities (acquired and congenital)
- Vitamin A deficiency
- Cloacal prolapse
- Urolithiasis
- Reproductive disease:
- Egg-binding/dystocia
- Follicular stasis
30
Q
What are the infectious diseases of chelonians
A
- Salmonella spp
- Mycobacteriosis
- Generalized abscesses
- Testudinid Herpesvirus
- Other herpesviruses too
- Ranavirus
- Mycoplasmosis
- Ulcerative shell disease
- Intranuclear Coccidiosis of Testudines (TINC)
*
31
Q
What are the nutritional requirements of chelonians?
A
- Range from herbivorous to omnivorous to carnivorous
- Herbivores
- Wide variety of greens
- certain veges
- very small amounts of fruits
32
Q
What is Hypovitaminosis D?
A
- 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
Q
How is Metabolic bone disease diagnosed
A
- 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
Q
What are the clinical signs of metabolic bone disease in chelonians
A
- Tremors
- weakness
- seizures when severe
- anorexia/hyporexia
- soft or deformed shell
- reluctance to move
35
Q
How is Metabolic bone disease treated/prevented
A
- 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)
- Expose to unfiltered sunlight
- Calcium supplementation
- high quality diet
- Calcium supplementation - injectable, oral
- Supportive care - fluids, heat, feeding
- Temperature, UV, humidity
36
Q
What is Vitamin A deficiency like in Chelonians? diagnostics? treatment?
A
- 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
- Secondary respiratory infections
- 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
Q
What is cloacal prolapse in chelonians? DDx?
A
- 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
Q
What is urolithiasis of chelonians? Dx? treatment?
A
- 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
Q
What reproductive diseases are in chelonians?
A
- 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
- correct husbandry
40
Q
What Trauma is commonly seen in chelonians? Treatment?
A
- 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
Q
What causes infectious diseases in chelonians?
A
- 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
Q
Why is it a concern for Chelonians to carry Salmonella spp
A
- 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)
- All taxa
43
Q
How is Salmonella carrier status assessed in chelonians
A
- 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
- Cannot be deemed free by treating with antibiotics
44
Q
What is Mycobacteriosis in chelonians?
A
- 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
- Difficult, not often recommended due to zoonotic concern
45
Q
What mycobacterium species are common to chelonians?
A
- M. chelonae
- M. szulgai
- M. marinum
- M. foruitum
- M. ulcerans
- M. leprae
- M. haemophilum
- M. avium
- M. kansasii
- M. terrae
- M. leptaemurium
46
Q
What are generalized abscesses in chelonians? Dx? Tx?
A
- 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
Q
What is Testudinind Herpesvirus? Clinical signs? Dx? Tx?
A
- 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
- Serologic tests - serum neutralization, ELISA, indirect immunoperoxidase
- Tx:
- Acyclovir or ganciclovir
- Supportive care
48
Q
What other herpesviruses exist in sea turtles
A
- Gray patch disease
- Fibropapillomatosis
- Lung, eye, trachea disease (LETD) virus
- Loggerhead genital-respiratory virus (LGRV)
- Loggerhead orocutaneous herpesvirus (LOCV)
49
Q
What other herpesviruses exist in freshwater turtles
A
Hepatitis
50
Q
What is Ranavirus in Chelonians? Signs? Dx? Tx?
A
- 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
- Clinical signs:
- High mortality Rate
- DX:
- CBC - Anemia, intracytoplasmic inclusions
- ELISA
- PCR, real-time PCR
- Virus isolation
- EM
- TX: acyclovir
51
Q
What is mycoplasmosis like in Chelonians?
A
- 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
Q
Clinical signs of mycoplasmosis?
A
- Rhinitis and nasal dishcarge
- Conjunctivitis and ocular discharge
- Palpebral edema
- Conjunctival hyperemia
- Chronic infections - grooves from nares, depigmentation around nares
53
Q
How is mycoplasmosis diagnosed in chelonians?
A
- Culture
- PCR (genus specific) - nasal swab or flush
- ELISA - Ab 6-8wks post infection ; passive transfer demonstrated
- Paired titers
54
Q
What is the treatment/prognosis of mycoplasmosis in chelonians
A
- Tx:
- Persisten infection and shedding
- no guidelines for treatment and release
- Enrofloxacin, clarithromycin, tulathromycin
- Persisten infection and shedding
- Prognosis:
- Acute mortality rare
- Some clear infection
- Most deveop chronic infections
- persistence in nasal epithelium with mucosal damage ⇢ ⇡ Susceptibility to secondary infections
- Most deveop chronic infections
- Death due to severe debilitation
55
Q
What causes Ulcerative shell disease
A
- “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
Q
What are teh clinical signs of Ulcerative shell disease
A
- 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
Q
How is ulcerative shell disease diagnosed? Tx?
A
- 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
Q
What is Intranuclear Coccidiosis of Testudines (TINC)?
A
- 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
Q
Clinical signs of TINC
A
- 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
Q
How is TINC diagnosed
A
- 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
Q
How is TINC treated?
A
- 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
Q
What is the prognosis of TINC
A
- Death common
- Treatment may eliminate organism, but histologically often com across tissue slcerosis (= long term organ effects)
