GI - Stomach pt 1

Question 1

List the 4 parts of the ruminant forestomach in order of food transit.

Answer 1

1. reticulum
2. rumen
3. omasum
4. abomasum

Question 2

Match the letters with the correct compartment of the ruminant fore stomach.

Answer 2

A: reticulum
B: Rumen
C: Abomasum
D: Omasum

Question 3

Like birds, camelids have ______ in their fore stomachs. However, unlike birds, they don’t serve a specific function; rather, they are incidental.

Answer 3

Gastroliths

Question 4

What type of epithelium lines the rumen?

Answer 4

stratified squamous epithelium

Question 5

What are trichobezoars?
Where are they found? Why?
What do they mean when found in necropsy?

Answer 5

spherical masses of hair or wool
found in the rumens of younger animals from excessive grooming.
Incidental finding

Question 6

What are phytobezoards?
What do they mean when found in necropsy?

Answer 6

Spherical masses of plant fibres
Incidental finding

Question 7

What are the gross lesions of ruminal hyperkeratosis?

Answer 7

club shaped, clumped papillae that may be dark

Question 8

what leads to ruminal hyperkeratosis?

Answer 8

diets high in concentrates
Vitamin A deficiency
high barley diets

Question 9

You are doing a necropsy of a cow and look at its rumen. What is your diagnosis? What do you think caused it?

Answer 9

Ruminal hyperkeratosis
diet high in concentrates, vitamin A deficiency, or a high barley diet

Question 10

What causes ruminal tympany? What’s the other name for this pathology?

Answer 10

inability to eructate gas from rumen
Bloat

Question 11

Ruminal tympany can lead to death through metabolic and physical effects. Name 2 of these effects.

Answer 11

Decreased venous return
Thoracic compression

Question 12

What are the gross lesions of ruminal tympany?

Answer 12

• marked abdominal distention with “sawhorse” posture
• blood is dark and clots poorly (indicates death from anoxia)
• subq hemorrhage/edema cranially, non-hemorrhagic edema caudally (inguinal is common) [cranial lymph nodes also affected]
• bloat line within esophagus [cranial congestion, becomes pale near thoracic inlet]
• lung compression/atelectasis

Question 13

A cow comes in with this posture. What is your primary differential based on this?

Answer 13

Ruminal tympany (bloat)
don’t know which type because we haven’t seen the rumen contents yet

Question 14

This is the esophagus of a cow. Based on the lesion seen in this photo, what is your diagnosis?

Answer 14

Ruminal tympany (bloat)
we don’t know the type because we haven’t looked at the rumen contents yet.

Question 15

What are the two main types of ruminal tympany? Label them as acute or chronic

Answer 15

Primary tympany = frothy bloat –> acute + severe
Secondary tympany = gas bloat –> chronic

Question 16

What causes primary ruminal tympany?

Answer 16

diet high in legumes (alfalfa, clover) or concentrates

Question 17

How can you tell that it’s primary ruminal tympany?

Answer 17

contents are frothy; gas trapped, not eructed
[froth will disappear with prolonged postmortem interval]

Question 18

What causes secondary ruminal tympany?

Answer 18

vagal indigestion syndromes
Ruminal drinkers

Question 19

how can you tell it’s secondary ruminal tympany?

Answer 19

gas is free but retained due to physical or functional defect
ruminal contents may look normal

Question 20

What are vagal indigestion syndromes?

Answer 20

clinical syndrome, gradual development of abdominal distention due to ruminoreticular distension

classically associated with damage to the vagus nerve; however, absence of vagal damage in the maj. of cases

most common cause is traumatic reticuloperitonitis

other causes include anything resulting in a mass effect near junctions b/t compartments (HANG acronym)

Question 21

What are ruminal drinkers?

Answer 21

milk escapes the ruminoreticular groove and ends up fermenting in the rumen

also have rumenitis histologically

Question 22

You receive a cow for necropsy that was in a “sawhorse” stance, and you find a bloat line in the esophagus. You look in the rumen and these are the contents. What is your diagnosis?

Answer 22

Primary ruminal tympany

Question 23

What is the other name for traumatic reticuloperitonitis? What location is most common for penetration?

Answer 23

hardware disease
cranioventral penetration

Question 24

What is traumatic reticuloperitonitis?

Answer 24

perforation of the fore stomach (classically the reticulum) due to a sharp foreign body (classically metallic)

Question 25

How do you prevent traumatic reticuloperitonitis?

Answer 25

Magnets!

Question 26

what are the possible outcomes for traumatic reticuloperitonitis? the first two you should defs know for exam

Answer 26

- Chronic local peritonitis +/- focal adhesions - traumatic pericarditis (requires diaphragmatic penetration) - subperitoneal or subq abscess near xyphoid - sudden death from hemorrhage (rare) - septicemia (rare) - pleuritis/pneumonia

Question 27

Which bacteria are commonly associated with traumatic reticuloperitonitis?

Answer 27

Trueperella pyogenes Fusobacterium necrophorum

Question 28

You find this item in this organ of a cow. What is your diagnosis? Name one bacterium you might find in this cow. Say this item travelled cranially and penetrated the diaphragm. What other lesion could you find?

Answer 28

Traumatic reticuloperitonitis Trueperella pyogenes or Fusobacterium necrophorum you could find traumatic pericarditis

Question 29

what causes ruminal acidosis?

Answer 29

ingestion of excessive carbohydrates more common in intense production systems more likely with sudden increase vs gradual

Question 30

How does the rumen pH change with ruminal acidosis? Give me normal values and changed values

Answer 30

normal rumen pH = 5.5 - 7.5 ruminal acidosis pH = ≤ 5

Question 30

Rumen pH generally _____ with postmortem interval.

Answer 30

increases

Question 31

What is the pathogenesis of ruminal acidosis?

Answer 31

decreasing pH leads to death of normal gram (-) bacteria --> proliferation of Streptococcus bovis --> increased lactic acid production --> decreased pH --> Lactobacillus predominates

Question 32

What are the gross lesions found with ruminal acidosis? (hint: they are pretty general)

Answer 32

sunken eyes, thick dark blood variable appearance to the ruminal contents, intestinal contents often watery mucosa may be difficult to peal may have a distinct odour tips of the ruminal papillae may appear white

Question 33

What are the specific outcomes of ruminal acidosis?

Answer 33

Scarring Necrobacillary rumenitis (AKA necrobacillosis) Mycotic rumenitis

Question 34

What is the etiology of necrobacillary rumenitis?

Answer 34

Fusobacterium necrophorum

Question 35

What are the gross lesions of necrobacillary rumenitis?

Answer 35

well-demarcated, plaque-like areas of necrosis bacterial embolization to the liver is common resulting in liver abscesses

Question 36

What is the etiology of mycotic rumenitis?

Answer 36

Zygomycete funguses (Mucor, Rhizopus, Absidia) Aspergillus also possible, but more common in abomasum

Question 37

What are the gross lesions of mycotic rumenitis?

Answer 37

more hemorrhagic, severe, and extensive than necrobacillary rumenitis often visible from the serosal surface vasculocentric --> causes infarcts (well demarcated areas of discolouration surrounded by a red rim)

Question 38

On the L is a rumen and on the R is a liver. What is your primary differential for the cause of these lesions? What is the etiology?

Answer 38

Necrobacillary rumenitis caused by fusobacterium necrophorum

Question 39

These are both examples of lesions associated with ______.

Answer 39

Mycotic rumenitis

Question 40

What is the scientific name of rumen flukes? What are the gross lesions? Pathogenic/non-pathogenic?

Answer 40

Paramphistomatidae sp. red to pink, similar in size to surrounding rumen papillae may be associated with some inflammation non-pathogenic

Question 41

These *things* are mixed in with rumen papillae. What is your primary differential?

Answer 41

Rumen flukes, Paramphistomatidae

Question 42

What is the name of the line formed by the division of the glandular and non-glandular portions of the equine stomach?

Answer 42

Margo plicatus

Question 43

What is the arrow pointing to? (pig stomach)

Answer 43

Pars esophagea

Question 44

What is the difference b/t a papilloma and a fibropapilloma?

Answer 44

papilloma is only epithelium proliferating, fibropapilloma is epithelium and underlying dermal mesenchyme

Question 45

Are fore stomach neoplasm common or rare?

Answer 45

rare

Question 46

What are the 3 fore stomach neoplasms that we need to know?

Answer 46

Fibropapilloma Papillomas Squamous cell carcinoma

Question 47

What is the etiology of fibropapillomas in the fore stomach? Where are you more likely to find them (specific)?

Answer 47

bovine papillomavirus 2 (BPV-2) esophagus and esophageal groove of the rumen

Question 48

What causes papillomas in the fore stomach? Where does it target?

Answer 48

bovine papillomavirus 4 only targets squamous mucosa

Question 49

Squamous cell carcinoma in the bovine fore stomach is associated with _____

Answer 49

BPV-4

Question 50

Label the green boxes in this bird stomach

Answer 50

L-most box: proventriculus R-most box: gizzard