Lecture 23/24: Reptilian GI Physiology (Wellehan)

Question 1

monophyletic group

Answer 1

group that contains all descendents from a common ancestor

Question 2

squamate

Answer 2

lizards + snakes

Question 3

first group to branch off from squamates

Answer 3

geckos

Question 4

main radiant heat source

Answer 4

the sun

Question 5

do most reptiles use radiant or contact heat sources in the wild?

Answer 5

radiant. It is difficult to maintain an even gradient with a contact heat source

Question 6

space heaters and aquarium heaters provide contact, radiant, or convective heat?

Answer 6

convective

Question 7

postprandial means:

Answer 7

after a meal

Question 8

How is postprandial metabolic rate affected by temperature?

Answer 8

Higher temp = faster metabolic rate

Question 9

Why are acrodont type teeth clinically relevant?

Answer 9

They are prone to periodontal disease and sloughing of the dental cascade. These type of teeth don’t continuously replace themselves
-common in chameleons

Question 10

lead poisoning in gators can lead to:

Answer 10

loss of teeth

Question 11

To do dental work on a gator, which nerve should be blocked?

Answer 11

mandibular

Question 12

Herpesviruses are common in which reptiles?

Answer 12

tortoises and lizards

Question 13

Where do herpesviruses reside histologically?

Answer 13

within host cell nuclei

Question 14

What other clinical signs are assoc. with lizard herpesvirus?

Answer 14

stomatitis and hepatitis

Question 15

Explain why cardio physiology is very important for GI in crocodiles *

Answer 15

Crocodiles have a complete vetricular septum unlike other reptiles. The right aortic arch is the main outflow of the heart, however the left aortic arch persists and carries less oxygenated blood. This blood with a higher CO2 can be carried to the stomach where it helps create a very low pH in the stomach. ligation of left aorta causes a decrease in gastric acid production

Question 16

Which animals have a complete ventricular septum?

Answer 16

mammals, birds, crocodiles.

Question 17

Foramen of Panizza

Answer 17

aperture b/w R and L aortic arches. Shrinks with adrenaline

Question 18

Subpulmonary conus

Answer 18

cog-tooth valve that blocks pulmonary outlfow. Opened by adrenaline

Question 19

In crocodiles, the right ventricle feeds which major arteries?

Answer 19

pulmonary and left aorta

Question 20

pathway of respiratory system in birds

Answer 20

trachea –> bronchi –> bronchioles –> lungs –> air capillaries –> air sacs

Question 21

increased bicarbonate –> O2 bound to hemoglobin

Answer 21

decreases. (causes O2 release)

Question 22

gastric acid secretion –> chloride, bicarbonate

Answer 22

depletes chloride, increases bicarb.

Question 23

clades of cryptosporidium are related by:

Answer 23

their trophic form (what part of the GI they infect)

Question 24

clinical signs of cryptosporidium

Answer 24

wasting, gastritis, enteritis, aural polyps. May be asymptomatic

Question 25

methods for diagnosing crypto

Answer 25

- acid fast staining - stomach washes - enzyme immunoassay - PCR (easiest method) - GI biopsy

Question 26

What are spirurids?

Answer 26

an order of nematodes, often found in gastric mucosa

Question 27

adenoviruses

Answer 27

diverse, stable, non-enveloped viruses found in reptiles. Usually host-specific. Commonly seen in co-infections. clinical signs = enteritis, hepatitis, etc.

Question 28

siadenovirus (a type of adenovirus) is found in which species

Answer 28

tortoises. >80% mortality rate! Never subclinical

Question 29

poster child for adenovirus

Answer 29

bearded dragons

Question 30

Methods of diagnosis for adenovirus

Answer 30

- electron microscopy - in situ hybridization - PCR

Question 31

treatment for adenovirus

Answer 31

cidofovir in mammals. No known treatment for reptiles

Question 32

Gastric neuroendocrine carcinoma

Answer 32

a somatostatin producing tumor found commonly in bearded dragons. Causes hyperglycemia

Question 33

How are bearded dragons and horses similar with respect to GI?

Answer 33

both are hind gut fermenters

Question 34

eat a meal --> growth and diversity of gut flora

Answer 34

increases. EXCEPT for bacteroidetes, which decreases after eating.

Question 35

eat a meal --> heart ventricular size, size of intestinal villi in pythons

Answer 35

both increase

Question 36

entamoeba invadens

Answer 36

pathogenic protozoal parasite of reptiles, causing colitis and gastritis. Tx = raise temperature (they are temp. sensitive)

Question 37

parabasalidea

Answer 37

- commonly found in normal animals - assoc. with flagellates - causes colitis - tx = metronidazole

Question 38

types of coccidia

Answer 38

intestinal, extraintestinal, intranuclear.

Question 39

methods of diagnosing coccidia

Answer 39

- intestinal: fecal flotation - extraintestinal: histology - PCR

Question 40

most effective tx for coccidia?

Answer 40

toltrazuril

Question 41

reovirus

Answer 41

- stable, unenveloped, rapidly reproducing segmented virus - easily reassorts; hard to vaccinate against - causes lipid depletion

Question 42

Do nematodes have direct or indirect lifecycle?

Answer 42

direct

Question 43

Do acanthocephala (thorny headed worms) have direct or indirect lifecycle?

Answer 43

indirect

Question 44

3 parts of cloaca

Answer 44

coprodeum, urodeum, proctodeum

Question 45

where is calcium first lost when a reptile makes an egg?

Answer 45

phalanges

Question 46

most common health problem in reptiles

Answer 46

obesity

Question 47

nutritionally simplest reptiles

Answer 47

snakes. All are carnivores, typically eat whole prey.

Question 48

T or F: venom may be necessary for digestion

Answer 48

T

Question 49

Why is it better to feed pre-killed prey to snakes?

Answer 49

no risk of injury, can be stored frozen. However, in feeding frozen fish there is a concern about thiaminase

Question 50

when do snakes typically eat their first meal?

Answer 50

After their first shed

Question 51

Common health problems in captive lizards

Answer 51

- dehydration - obesity - underfeeding - incorrect Ca:P ratio in food - Vit. D toxicity

Question 52

what causes tongue incoordination in chameleons?

Answer 52

Ca deficiency

Question 53

piscivorous means:

Answer 53

eats fish

Question 54

what are chelonians?

Answer 54

turtles and tortoises

Question 55

prolapses in chelonians are often assoc. with

Answer 55

vitamin A deficiency

Question 56

common health problems in captive chelonians

Answer 56

- secondary hyperparathyroidism to nutritional problem - vit. A deficiency - thiamine deficiency

Question 57

lizards require sunlight for:

Answer 57

vitamin D metabolism

Question 58

herbivorous chelonians are prone to:

Answer 58

nutritional secondary hyperparathyroidism, fiber deficiency, calcium deficiency