Gastric pathology in dogs

Question 1

What is associated with acute gastritis?

Answer 1

Long term NSAID use
Stress
Systemic infections
Ischaemia and shock
Mechanical trauma
**No evidence for infections agents**

Question 2

How can a gastric foreign body act?

Answer 2

If lodged in the pylorus - acute gastritis signs

Otherwise just causes mechanical trauma

Question 3

How is chronic gastritis characterised?

Answer 3

Intermittent vomiting for greater than 1-2 weeks

Question 4

How is chronic gastritis characterised?

Answer 4

Predominant cell type (eosinophilic, lymphoplasmacytic, granulomatous, lyphoid follicular)
Architectural abnormalities (ulceration, oedema, metaplasia, atrophy, hyperplasia, fibrosis)

Question 5

Outline lymphoplasmacytic gastritis

Answer 5

Most common form
Can be in combination with enteritis/ colitis as part of IBD
Middle aged to older animals
No breed disposition
Infiltration of lymphocytes/ plasma cells into lamina propria
Sometimes associated with helicobacter

Question 6

Outline granulomatous gastritis

Answer 6

Can occur with infectious diseases, reactions to foreign material, reaction to endogenous substances
Infections - histoplasmosis, crytococcus, pythium insidiosm

Question 7

Outline eosinophilc gastritis

Answer 7

Generalised GI tract hypersensitivity
Normally dogs less than 5 years old
GSDs and Rotties predisposed

Question 8

What is scirrhous EG?

Answer 8

Rare variant of eosinophilic gastritis

Stomach very enlarged with a very thickened wall

Question 9

How can Addisons lead to ulcers?

Answer 9

Systemic hypovolaemia leads to a decrease in mucosal blood flow
A loss of the permissive effect of glucocorticoids in mucosal defense
Electrolyte abnormalities

Question 10

How can hepatic disease cause gastric ulceration?

Answer 10

Altered gastric blood flow due to portal hypertension
Delayed epithelial turnover
Gastric hyperacidity
Hypergastrinaemia

Question 11

How can MCTs lead to gastric ulcers

Answer 11

They release histamine
This binds to H2 receptors on gastric parietal cells
Leads to acid secretion

Question 12

What does and NSAID ulcer look like grossly?

Answer 12

Normally less than 2cm diameter
Punched out appearance
Antropyloric area

Question 13

What would an acute ulcer look like grossly?

Answer 13

Small

Regular slightly raised border

Question 14

What would a chronic ulcer look like grossly?

Answer 14

Large, can fluctuate in size
Elevated borders
Needs to be differentiated from neoplasia on histopathology

Question 15

What is giant hypertrophic gastritis?

Answer 15

Rare in dogs

Marked thickening of the gastric wall

Question 16

What is chronic hypertrophic pyloric gastropathy?

Answer 16

Syndrome of pyloric obstruction which can be caused  by either:
1. hypertrophy of the circular muscle of the pylorus (congenital - boxers/ bulldogs/ boston terriers)
2. Hyperplasia of the antropyloric mucosa with local inflammation (middle aged to older small breed dogs)
3. A combination
Unclear pathogenisis (possibly stress  or neuroendocrine related)

Question 17

What types of polyp are there?

Answer 17

Non-neoplastic (rare)

Neoplastic

Question 18

What types of metaplasia are there?

Metaplasia = potentially reversible change from one fully differentiated cell type to another

Answer 18

Osseous
Glassy cell change
Mucous cell

Question 19

What types of gastric neoplasia are there?

Gastric neoplasia accounts for less than 1% of all canine neoplasia

Answer 19

Carcinoma (50-90% - poor prognosis)
Leiomyoma
MCT (rare)
Lymphoma
Histiocytic sarcoma

Question 20

Outline gastric carcinomas

Answer 20

Normally start in the lesser curvature and pylorus
More in males
Belgian Shepherd dogs, standard poodles. staffies, rough collies
Often diagnosed late - 70-90% already have mets
Median survival time 35d

Question 21

Outline leiomyomas

Answer 21

Benign smooth muscle cells
Older male dogs mostly
Found in cardia or gastro-oesophageal junction
The mucosa tends to remain intact so ulceration is rarer, haemorrhage uncommon

Question 22

Outline gastric lymphoma

Answer 22

Can be primary GIT or part of multicentric

If primary GI - T cell