Amphibians Flashcards

Question

Osmolarity of Environmental Fluid and Fluid Uptake in Amphibians

Answer 1

Osmolarity of environmental fluid important: difference between external and plasma osmolality determines water regulation/movement ■ Change composition of plasma to tolerate fluctuations in water osmolality ■ Imbalance = fluid overload (kidney compromise) High permeability allows absorption of exogenous compounds (drugs/toxin)

Answer 2

--Occur prior to GA, detect abN that may increase risk --Observe in enclosure: activity, demeanor, breathing pattern, hydration --Gentle restraint to prevent escape, failing: brief, efficient stress free, safe --Expect sudden bursts of activity to escape

Answer 3

Premoistened Talc-free latex gloves: reduce risk of skin damage/transfer of pathogens/toxins btw handler, animal +/- protective eye wear Washed vinyl gloves for larvae Water/fluid to moisten should be distilled, dechlorinated to prevent chlorine uptake - consider non-toxic, water soluble gel provides better protection for animals with sensitive skin Some frogs/toads will bite; salamanders will drop tails

Answer 4

Some species urinate when stressed ● Lack of behavior may indicate dehydration Dehydration may present with skin tenting, sunken eyes, tacky skin, slow/decreased activity/mentation

Answer 5

Common Problem Tetany, muscle fasciculations, paresis, GI stasis, bloating ■ Treated with calcium gluconate in a bath Calcium readily absorbed through skin ■ Blood chemistry analysis performed after induction (minimize stress)

Answer 6

Not generally necessary: can maintain a closed larynx ○ Reserved for large species that eat rodent prey 24-48 hours prior to anesthesia to decrease risk of ileus and facilitate visualization during coelomic procedures

Answer 7

**TOPICAL** Drugs delivered in water, absorbed across gills or skin --Inhalants can be administered topically or in solution --Induction prolonged or unsuccessful if bubbled through water Some species can be intubated awake and administered inhalants

Answer 8

■ Low margin of safety ■ Prolonged recovery ■ Doses species specific

Answer 9

**Bath solution for induction: dose dependent on surface area of animal** ■ Ie. small patients may be exposed to more drug **Tank water from enclosure should be used** ○ Reduces exposure to abrupt pH/temp changes ○ Can use bottled spring water at room temp ○ Can prepare “Amphibian Ringers” solution Container used should be thoroughly cleaned and rinsed

Answer 10

Container used should be thoroughly cleaned and rinsed ○ Cleaning chemicals can be toxic if absorbed ○ Rinse well between patients due to secretions may be toxic

Answer 11

Reduced or absent during anesthesia ○ Cutaneous gas exchange may be low ○ Supplement oxygen to avoid hypoxemia and acidemia

Answer 12

Supplement oxygen to avoid hypoxemia and acidemia ■ Bubble oxygen into water bath ■ Intubate to provide O2 IV catheters with adaptors, Cole tubes for larger species Ventilate gently to avoid lung damage ● 5 cmH20, every 10 seconds

Answer 13

○ Procedure to be performed ○ Level of immobilization required ○ Duration of anesthesia

Answer 14

● Skin kept moist to prevent damage/dehydration, ensure dermal respiration maintained

Answer 15

Tricaine Methanesulfonate; Finquel®) Most commonly used Wide margin of safety; effective in all species, life stages Requires buffering with sodium bicarbonate to pH 7.0-7.4 (highly acidic) MOA: Sodium channel blocker, inhibiting nerve conduction ■ CNS depression

Answer 16

Some species urinate when stressed: lack of behavior may indicate dehydration Dehydration may present with skin tenting, sunken eyes, tacky skin, slow/decreased activity/mentation

Answer 17

Administered via immersion Species-specific different responses Dosing difficult as concentration of eugenol may not be known

Answer 18

Commonly causes **gastric prolapse** due to pungent taste cause **renal tubular apoptosis** ■ Hepatic necrosis, hemorrhage of coelomic fat bodies reported **cutaneous necrosis** if applied directly to skin

Answer 19

1. Cutaneous Administration 2. Bubbled through H2O

Answer 20

(mixed with KY jelly) ■ Species-specific variability in effects

Answer 21

MOA: local anesthetic ■ Blocks Na-Voltage gated channels and TRPV1 ■ Activates inhibitory GABA receptors

Answer 22

■ High exposure levels of waste gas - use a sealed container but makes handling difficult ■ **Induction time = SLOW, recovery = RAPID** once removed from bath

Answer 23

○ Needs to be dissolved in ethanol first ■ Final concentration should not exceed 1%

Answer 24

Propofol, ketamine, alfaxalone, 𝝰2-adrenergic agonists show wide species variability ■ Unpredictable inductions and recoveries ■ Undesirable mortality rates

Answer 25

○ Chemical restraint and sedation but not surgical anesthesia

Answer 26

not routinely performed ○ Administration of analgesic with/without sedative prior to induction may be beneficial in larger species

Answer 27

--Baseline HR obtained prior to anesthesia or immediately after induction to allow a trend to be formed ○ **Relatively low heart rates (50bpm)** ○ Visualization or with doppler probe at heart --**Good indicator about depth** --Sudden drop or slow decrease in time: increase in depth ECG (avoid skin damage), Doppler, Visualization

Answer 28

Change concentration of the bath Syringes of premade solution (with and without anesthetic) can be used to deepen/lighten anesthesia as necessary by flushing over skin

Answer 29

Cessation of movement, righting reflex is first indication of induction Light stage: loss of righting reflex, loss of abdominal breathing Surgical depth: loss of withdrawal (with toepinch) and no gular respiration

Answer 30

Pulse oximeter is not validated ○ Used to monitor trends Provide thermal support, fluid uptake and analgesia

Answer 31

prolonged but usually smooth ○ Close monitoring to reduce complications ○ Phase of excitemen, erratic movements may be seen Residual topical anesthetic rinsed off ○ Skin kept moist Recovery on room air

Answer 32

Return of Withdrawal reflexes → increase in gular respiration → righting reflex → movement with improving coordination

Answer 33

● Recovery Process: Return of Withdrawal reflexes → increase in gular respiration → righting reflex → movement with improving coordination

Answer 34

--Well established, opioids effective analgesics Dermorphin Deltorphine

Answer 35

Potent amphibian-specific opioid compound found in skin of some SA frog species ■ 40x more potent than morphine ■ Potent 𝝻-agonist DERMORPH = MORPH IN SKIN

Answer 36

endogenous opioid peptide from skin ■ Potent 𝛅-receptor agonist ■ May play role in protection from predators/role in hibernation

Answer 37

Comparable to mammalian: --Large and medium myelinated A-fibers, small myelinated B-fibers, small unmyelinated C-fibers --Substance P, glutamate present in spinal cord Peripheral sensitization to noxious stimuli can occur Ascending pathways not fully understood

Answer 38

● Species-specific differences likely ○ Unable to extrapolate from one species to the next

Answer 39

dose-dependent effect ■ Receptor selectivity less than mammals ■ Relative potency mu > delta > kappa ■ Doses higher than mammals ● Onset to peak analgesic effect longer: >60’

Answer 40

○ Provides analgesia without sedation ■ Normal reflexes remain intact ○ Rapid onset, long lasting

Answer 41

○ Little data exists Flunixin meglumine reported to provide analgesia ■ High dose required (25mg/kg) ■ One animal died, had evidence of renal congestion and inflammation Meloxicam reduced circulating prostaglandins ■ No significant effect in analgesic trials Indomethacin and ketorolac provided mild analgesia in two studies

Amphibians Flashcards

(65 cards)