Stomach

Question 1

What causes gastroduodenal ulceration?

Answer 1

Disequilibirum between mucosal aggressive factors (hydrochloric acid, pepsin, bile acids, organic acid) and protective factors (mucus and bicarbonte)

Question 2

Where are mucosal protective factors more developed?

Answer 2

In the glandular mucosa

Question 3

What is the cause of ulcers in the squamous mucosa

Answer 3

Fasting
Infrequent feeding and recumbency (low gastric pH in foals) → prolonged exposure to acid
Feed deprivation
Time of feeding and type of roughage source
Concurrent dz or gastric outflow obstruction, ↓ gastric motility, or delayed gastric emptying
Desquamation of squamous epithelium in foals

Question 4

Which types of roughage is good for gastric ulcers?

Answer 4

Alfalfa (less acidity and lower gastric ulcer scores)
High protein and Ca concentration provide buffering of acid 5 hrs after feeding
Stimulate production of bicarb rich saliva

Question 5

Squamous gastric ulcers frequent with _______

Answer 5

Performance horses → prolonged exposure to acid, exercise and abdominal pressure

Question 6

Which organic acids act synergistically with hydrochloric acid?

Answer 6

Volatile fatty acids: fermentation byproducts of carbohydrates induce injury to gastroesophageal (squamous) mucosa → penetrate squamous mucosa when acid concentrations high → cell damage, inflamm. and ulceration

Question 7

Causes of ulcers in the glandular mucosa

Answer 7

Due to disruption of blood flow and ↓ mucus and bicarb secretion
Back diffusion of H+ ions and damage
Inhibition of PGs

Question 8

What does blocking PG synthesis do?

Answer 8

↓mucosal blood flow, stimulate gastric acid secretion and inhibits bicarb
Stop production of surface- acting phospholipids

Question 9

What inhibits PGs?

Answer 9

NSAIDs
Endogenous corticosteroids, parturition, training and confinement

Question 10

CS of gastroduodenal ulcers in foals

Answer 10

Intermittent colic after suckling/ eating
Interrupted nursing due to discomfort
Diarrhea or history of diarrhea
Pyloric obstruction (bruxism- grinding teeth and ptyalism)

Question 11

Advanced gastroduodenal ulceration

Answer 11

Partial blockage of the duodenum due to the structure by scar formation
Disrupts gastric emptying —> secondary squamous gastritis and esophagitis

Question 12

CS of gastroduodenal ulceration in adult horses

Answer 12

Poor appetite, fullness, attitude changes, decreased performance, reluctance to train, poor body condition, rough hair coat, WL, excessive recumbency, and low-grade colic

Question 13

Definitive dx of gastroduodenal ulcers

Answer 13

Fiberoptic endoscope
5-6 ft in foals, 11 ft in horses

Question 14

What is the most common medical cause of gastroduodenal ulcers in horses?

Answer 14

Phenyl-butazone toxicity
usually just stress from clinics

Question 15

Main tx for gastroduodenal ulcers

Answer 15

Omeprazole: inhibits gastric acid secretion

Question 16

Other gastroduodenal ulcer tx

Answer 16

Type 2 histamine antagonists: cimetidine, ranitidine
Magnesium hydroxide antacids
Sucralfate (mucosal protectant)

Question 17

Sx tx for ulcers in foals

Answer 17

Pylorus: gastrojejunostomy
Duodenum (prox to heparicopancreatic ampulla): gastroduodenostomy
Duodenum (distal to heparicopancreatic ampulla): duodenojejunostomy
Pylorus and duodenum: subtotal gastrectomy and gastroduodenostomy

Question 18

Complications for ulcers

Answer 18

Adhesions
Septic peritonitis
Blind loop syndrome
Reflux alkalotic gastritis

Question 19

Prognosis for ulcers

Answer 19

Duodenal structures have the worst prog
30-50% for life on average