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
27
Q
How can radiographs be taken of chelonians?
A
- Small patients - use dental radiographs
- Positioning:
- Dorsoventral
- Lateral (horizontal beam)
- Craniocaudal (horizontal beam)
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
