EGUS Flashcards
Frequent clinical signs of horses with EGUS
- Not performing well
- Not finishing feed
- Variable and often vague
- Can have completely normal physical exams
Glandular and non-glandular stomach
- Orad 1/3 lined with stratified squamous epithelium (non-glandular)
- Ends at margo plicatus
- Glandular portion is the aborad 2/3 (compound columnar)
What stimulates acid and histamine?
- Histamine stimulates acid
- Gastrin stimulates histamine
pH of the region near the pylorus?
1-2
pH of the region near the glandular fundus
- Medium density mat
- pH 4-5
pH of the region near the margo plicatus
- Low density mat
- pH 5-7
How long should liquid contents take to go through the stomach vs solid contents?
- Liquid contents take ~30 min
- Solid contents take ~1-5 hours
What cells are in the oxyntic portion of the glandular mucosa?
- Acid secreting parietal cells
- Pepsinogen secreting chief cells
- Histamine secreting cells
- Somatostatin secreting cells
What cells are in the antral region of the stomach?
- Mucus and mucin secreting cells
- Endocrine cells
- Gastrin secreting G cells
What are the three types of EGUS?
- ) Primary squamous ulceration
- ) Primary glandular ulceration
- ) Secondary squamous ulceration
Primary squamous ulceration
- Increased acid exposure
- Alteration in gastric pH gradient and content stratification
Primary glandular ulceration
- Acid exposure occurs
- FAILURE of mucosal defenses
Secondary squamous ulceration
- Delayed gastric emptying (pyloric disease)
- Increases residual gastric fluid volume
- Dorsal movement of acid
Factors that impact primary squamous ulcer formation
- Horses on pasture and light exercises (low prevalence of ulcers)
- Starvation produces prolonged high gastric acidity (pH<2) - horses fed fewer times a day have an increased risk of ulceration
- Consistent fresh water important (will increase risk factor of EGUS by 3)
- Fermentation of soluble carbohydrates with stomach produce VFA that can penetrate the squamous epithelium and cause cell damage
- High starch diet increases risk factors
- Exercise (increased intrabdominal pressure combined with lowered intragastric pH)
- Duration of acid exposure related to duration and intensity of exercise
- Stress
Do NSAIDs cause gastric ulcers?
- No
- If at normal dose of NSAIDs and they eat, it won’t cause ulceration
- They can lead to ulceration of the right dorsal colon
Glandular ulcer causes
- Unknown pathogenesis
- Acid can exacerbate tissue injury
- Ulceration may reduce diversity and lead to colonization of opportunistic bacteria
Clinical pathologic abnormalities of horses with colic
- No consistent clinical pathologic abnormalities
- Sometimes slight anemia and lowered hemoglobin
Is colic associated with EGUS?
- Not as much
- Reduced appetite and decreased performance is more likely
Diagnosis of EGUS?
- History
- PE
- Confirm with gastroscopy (GOLD STANDARD) - MUCH better than the fecal occult blood test for specificity and sensitivity
Prevalence of ulcers
- varies with breed and level of training
- Most racehorses in full training have ulcers
Prevalence of gastric squamous ulcers and glandular ulcers
- Similar prevalence
- No association between presence and severity
- No correlation between squamous and glandular ulcers
Healing time of squamous vs glandular ulcers
- Squamous ulcers heal faster
- Glandular ulcers can take 3-6 months
- Squamous ulcers can heal within 21 days
How to confirm healing after treatment of ulcers?
- Gastroscopy
What therapy might glandular ulcers need?
- Antimicrobial therapy (dysregulation of microbiota)
- Misoprostal
