GI - Stomach pt 2 Flashcards
Which breeds are more susceptible to canine gastric dilation and volvulus?
deep-chested dogs (Great Danes, st. Bernards, Irish setters, wolfhounds, bloodhounds, German shepherds)
Explain the pathogenesis of a complete canine gastric dilation and volvulus (GDV) from onset to death.
- Accumulation of gas in the stomach, causing it to swell and bloat
- stomach rotates about esophagus in a clockwise direction when viewed from the caudal aspect (180-360 degrees)
- severe torsion leads to more occlusion of the esophagus and vascular compromise
- starting with mucosa and progressing through gastric wall, you get dark red to purple discolouration and edema
- vascular supply to spleen compromised
- circulatory shock, gastric rupture, respiratory compromise
- death (if no intervention)
This is a dog. What is your top differential for death?
GDV that was untreated
Equine gastric dilation and volvulus can be primary or secondary. What are the causes of primary AND secondary equine GDV?
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
What are the consequences of equine GDV?
laminitis
gastric rupture
What is the cause of gastric rupture in relation to equine GDV?
idiopathic, no specific cause identified
is gastric rupture due to equine GDV fatal?
YES. death is rapid
what does gastric rupture b/c of equine GDV target?
greater curvature parallel to omental attachment
How do you distinguish a pre-mortem vs a post-mortem gastric rupture in a horse?
- see bloat line in esophagus, hemorrhage/edema at margins of rupture
- Post-M gastric rupture– see thin wall and multiple holes
Does a chronic form of gastric dilation occur in horses?
YES
Bovine abomasal displacement:
what is the common signalment?
is it a clinical or necropsy thing usually?
majority are ____ displacement (R or L)?
high-producing dairy cows, esp at parturition
more of a clinical problem, rare necropsy cases
left displacement
Does R or L abomasal displacement lead to abomasal volvulus?
What does abomasal vovulus lead to ?
R displacement leads to abomasal vovulus
leads to metabolic alkalosis and abomasal rupture
What are the frequent concurrent conditions that cows have while also having abomasal displacement?
ketosis
hypocalcemia
metritis
retained placenta
What other species get GDV other than equine, canine, or bovine?
pigs, guinea pigs
What is the etiology of clostridial abomasitis?
Clostridium septicum
What species/signalment are usually affected by clostridial abomasitis? In one of the species/signalments, it has a different name … what is it?
calves & sheep
called Braxy in sheep
Clostridial abomasitis:
What is the climate where this happens?
What are clinical signs due to?
What are the gross findings?
histo findings?
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
This is the “bubble wrap” texture of _______ (pathology). This is caused by ____ & _____ (specific gross findings)
Clostridial abomasitis
emphysema & edema
What are the etiologies of mycotic abomasitis? What is this pathology similar to? What does it result in?
Zygomycetes & Aspergilus
similar to mycotic ruminitis
results in thrombosis & infarction
This is the abomasum of a cow. What did this cow likely die of?
Mycotic abomasitis
What are the equine stomach parasites that we need to know?
Gasterophilus (intestinalis & nasalis)
This is a horse stomach. What is the lesion?
Gasterophilus spp (probably intestinalis, but not specifically said)
What are the stomach parasites we need to know for cattle/sheep/goats?
Ostertagia spp
Haemonchus spp.
Haemonchus contortus = sheep & goats
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?
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
What is the porcine stomach parasite that we need to know? what do the lesions resemble?
Hyostrongylus rubidus AKA red stomach worm of pigs
resemble Ostertagia of ruminants
This is a bison abomasum. What is your primary differential for pathology? What is the specific lesion? What is the chronicity [acute vs chronic]?
Ostertagia spp
Chronic
raised nodules of mucosa –> moroccan leather appearance
What is the common name for Hemonchosis? What does this pathology result in and why?
barber pole worm
results in anemia and hypoproteinemia
b/c it feeds on blood
What are the gross lesions of hemonchosis?
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
What lesion does this cattle have?
Subq edema –> bottle jaw
Gastroduodenal & abomasal ulcers:
- why do they occur?
- what is the progression?
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)
What are the gross findings of gastroduodenal/abomasal ulcers?
what does the pathogenesis include?
melena & the actual ulcers
pathogenesis include coagulative necrosis
Where are gastroduodenal ulcers most common in dogs? (I want specific locations)
pyloric antrum of stomach and within the proximal duodenum
what are the causes of gastroduodenal ulcers in dogs? what is/are the concurrent conditions?
gastroduodenal tumors –> adenocarcinoma, lymphoma
other tumors –> cutaneous mast cell tumors, gastrinoma
drugs –> NSAIDs, glucocorticoids
concurrent conditions –> liver disease
Why do cutaneous mast cell tumors cause gastroduodenal ulcers in dogs?
tumor produces histamine, which stimulates increased acid secretion
why do gastrinomas cause gastroduodenal ulcers in dogs?
It’s a gastrin secreting tumor, and gastrin stimulates HCl secretion
Gastrinoma-induced gastroduodenal ulcers in dogs go by a different name. What is it?
Zollinger-Ellison syndrome
This lesion is in a dog stomach. What is the pathological condition? Give me 3 potential causes.
Gastroduodenal ulcer (gastric ulcer, really)
causes: adenocarcinoma, lymphoma, cutaneous mast cell tumor, gastrinoma, NSAID toxicity, glucocorticoid toxicity
Why does NSAID toxicity cause gastroduodenal ulcers in dogs?
inhibits bicarbonate secretion, decreased mucosal protection
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?
Abomasal
small stress associated ulcers
calves < 4mo
Where do ulcers in pigs target? What is the cause? What is the usual result?
what do the ulcers smell like?
pars esophagea
cause = finely ground feed
acute death from exsanguination
may smell like apple cider
Horse gastroduodenal ulcers:
- common or uncommon? Incidental?
- what can they cause?
- frequent signalment?
- common location?
- common, usually incidental
- can cause colic
- foals < 4mo
- squamous portion immediately adjacent to margo plicatus
What are the epithelial tumors of the stomach/abomasum that we need to know? and what are the species affected?
- Squamous cell carcinoma –> squamous portion of horse stomach
- adenocarcinoma –> dogs
What is the mesenchymal tumor of the stomach/abomasum that we need to know?
leiomyoma
What are the round cell tumors of the stomach/abomasum that we need to know?
abomasal lymphoma of cattle
mast cell tumors (dogs > cats)
