GI - Stomach pt 2

Question 1

Which breeds are more susceptible to canine gastric dilation and volvulus?

Answer 1

deep-chested dogs (Great Danes, st. Bernards, Irish setters, wolfhounds, bloodhounds, German shepherds)

Question 2

Explain the pathogenesis of a complete canine gastric dilation and volvulus (GDV) from onset to death.

Answer 2

1. Accumulation of gas in the stomach, causing it to swell and bloat
2. stomach rotates about esophagus in a clockwise direction when viewed from the caudal aspect (180-360 degrees)
3. severe torsion leads to more occlusion of the esophagus and vascular compromise
4. starting with mucosa and progressing through gastric wall, you get dark red to purple discolouration and edema
5. vascular supply to spleen compromised
6. circulatory shock, gastric rupture, respiratory compromise
7. death (if no intervention)

Question 3

This is a dog. What is your top differential for death?

Answer 3

GDV that was untreated

Question 4

Equine gastric dilation and volvulus can be primary or secondary. What are the causes of primary AND secondary equine GDV?

Answer 4

Primary:
- consumption of excess fermentable carbs
- sudden access to lush pasture
- excessive water intake

secondary:
- physical/functional obstruction of the stomach outflow, small bowel outflow, or ileus

Question 5

What are the consequences of equine GDV?

Answer 5

laminitis
gastric rupture

Question 6

What is the cause of gastric rupture in relation to equine GDV?

Answer 6

idiopathic, no specific cause identified

Question 7

is gastric rupture due to equine GDV fatal?

Answer 7

YES. death is rapid

Question 8

what does gastric rupture b/c of equine GDV target?

Answer 8

greater curvature parallel to omental attachment

Question 9

How do you distinguish a pre-mortem vs a post-mortem gastric rupture in a horse?

Answer 9

• see bloat line in esophagus, hemorrhage/edema at margins of rupture
• Post-M gastric rupture– see thin wall and multiple holes

Question 10

Does a chronic form of gastric dilation occur in horses?

Answer 10

YES

Question 11

Bovine abomasal displacement:
what is the common signalment?
is it a clinical or necropsy thing usually?
majority are ____ displacement (R or L)?

Answer 11

high-producing dairy cows, esp at parturition
more of a clinical problem, rare necropsy cases
left displacement

Question 12

Does R or L abomasal displacement lead to abomasal volvulus?

What does abomasal vovulus lead to ?

Answer 12

R displacement leads to abomasal vovulus

leads to metabolic alkalosis and abomasal rupture

Question 13

What are the frequent concurrent conditions that cows have while also having abomasal displacement?

Answer 13

ketosis
hypocalcemia
metritis
retained placenta

Question 14

What other species get GDV other than equine, canine, or bovine?

Answer 14

pigs, guinea pigs

Question 15

What is the etiology of clostridial abomasitis?

Answer 15

Clostridium septicum

Question 16

What species/signalment are usually affected by clostridial abomasitis? In one of the species/signalments, it has a different name … what is it?

Answer 16

calves & sheep
called Braxy in sheep

Question 17

Clostridial abomasitis:
What is the climate where this happens?
What are clinical signs due to?
What are the gross findings?
histo findings?

Answer 17

Temperate
exotoxin production
Gross findings: hemorrhagic ascites, congested serosa and abomasal wall +/- fibrin, abomasal wall thickened by emphysema and edema (also hemorrhagic) [bubble wrap]
histo findings: areas of coagulative necrosis, gram + bacilli

Question 18

This is the “bubble wrap” texture of _______ (pathology). This is caused by ____ & _____ (specific gross findings)

Answer 18

Clostridial abomasitis
emphysema & edema

Question 19

What are the etiologies of mycotic abomasitis? What is this pathology similar to? What does it result in?

Answer 19

Zygomycetes & Aspergilus
similar to mycotic ruminitis
results in thrombosis & infarction

Question 20

This is the abomasum of a cow. What did this cow likely die of?

Answer 20

Mycotic abomasitis

Question 21

What are the equine stomach parasites that we need to know?

Answer 21

Gasterophilus (intestinalis & nasalis)

Question 22

This is a horse stomach. What is the lesion?

Answer 22

Gasterophilus spp (probably intestinalis, but not specifically said)

Question 23

What are the stomach parasites we need to know for cattle/sheep/goats?

Answer 23

Ostertagia spp
Haemonchus spp.
Haemonchus contortus = sheep & goats

Question 24

for cattle/sheep/goat ostertagiasis, where does larval development occur? What are the gross lesions [for both acute and chronic]? What are the histo lesions?

Answer 24

development = abomasum
gross lesions:
- acute lesion - marked edema, multifocal nodules
- chronic lesion - mucosa thickened, raised nodules (Moroccan leather appearance)
histo lesions:
- mucous metaplasia and hyperplasia

Question 25

What is the porcine stomach parasite that we need to know? what do the lesions resemble?

Answer 25

Hyostrongylus rubidus AKA red stomach worm of pigs resemble Ostertagia of ruminants

Question 26

This is a bison abomasum. What is your primary differential for pathology? What is the specific lesion? What is the chronicity [acute vs chronic]?

Answer 26

Ostertagia spp Chronic raised nodules of mucosa --> moroccan leather appearance

Question 27

What is the common name for Hemonchosis? What does this pathology result in and why?

Answer 27

barber pole worm results in anemia and hypoproteinemia b/c it feeds on blood

Question 28

What are the gross lesions of hemonchosis?

Answer 28

pallor (b/c of anemia) SubQ edema --> results in edema called bottle jaw tricavitary effusion (hydrothorax, hydropericardium, ascites) watery dark red-brown abomasal contents can see worms by naked eye

Question 29

What lesion does this cattle have?

Answer 29

Subq edema --> bottle jaw

Question 30

Gastroduodenal & abomasal ulcers: - why do they occur? - what is the progression?

Answer 30

an imbalance b/t corrosive effects of gastric acid & pepsin, vs the resilience/defences of mucosa - either an impairment in mucosal integrity OR hyper secretion of acid progress from erosion to ulcer to perforation (which can be silent, cause a pancreatitis, or a septic peritonitis)

Question 31

What are the gross findings of gastroduodenal/abomasal ulcers? what does the pathogenesis include?

Answer 31

melena & the actual ulcers pathogenesis include coagulative necrosis

Question 32

Where are gastroduodenal ulcers most common in dogs? (I want specific locations)

Answer 32

pyloric antrum of stomach and within the proximal duodenum

Question 33

what are the causes of gastroduodenal ulcers in dogs? what is/are the concurrent conditions?

Answer 33

gastroduodenal tumors --> adenocarcinoma, lymphoma other tumors --> cutaneous mast cell tumors, gastrinoma drugs --> NSAIDs, glucocorticoids concurrent conditions --> liver disease

Question 34

Why do cutaneous mast cell tumors cause gastroduodenal ulcers in dogs?

Answer 34

tumor produces histamine, which stimulates increased acid secretion

Question 35

why do gastrinomas cause gastroduodenal ulcers in dogs?

Answer 35

It's a gastrin secreting tumor, and gastrin stimulates HCl secretion

Question 36

Gastrinoma-induced gastroduodenal ulcers in dogs go by a different name. What is it?

Answer 36

Zollinger-Ellison syndrome

Question 37

This lesion is in a dog stomach. What is the pathological condition? Give me 3 potential causes.

Answer 37

Gastroduodenal ulcer (gastric ulcer, really) causes: adenocarcinoma, lymphoma, cutaneous mast cell tumor, gastrinoma, NSAID toxicity, glucocorticoid toxicity

Question 38

Why does NSAID toxicity cause gastroduodenal ulcers in dogs?

Answer 38

inhibits bicarbonate secretion, decreased mucosal protection

Question 39

Cattle stomach ulcers: - Which location is more common: abomasal or duodenal? - What is the most common cause of ulcers? - Perforating abomasa ulcers are common in what signalment?

Answer 39

Abomasal small stress associated ulcers calves < 4mo

Question 40

Where do ulcers in pigs target? What is the cause? What is the usual result? what do the ulcers smell like?

Answer 40

pars esophagea cause = finely ground feed acute death from exsanguination may smell like apple cider

Question 41

Horse gastroduodenal ulcers: - common or uncommon? Incidental? - what can they cause? - frequent signalment? - common location?

Answer 41

- common, usually incidental - can cause colic - foals < 4mo - squamous portion immediately adjacent to margo plicatus

Question 42

What are the epithelial tumors of the stomach/abomasum that we need to know? and what are the species affected?

Answer 42

- Squamous cell carcinoma --> squamous portion of horse stomach - adenocarcinoma --> dogs

Question 43

What is the mesenchymal tumor of the stomach/abomasum that we need to know?

Answer 43

leiomyoma

Question 44

What are the round cell tumors of the stomach/abomasum that we need to know?

Answer 44

abomasal lymphoma of cattle mast cell tumors (dogs > cats)