Intestinal Pathology Flashcards
What is the difference between malabsorption and maldigestion?
Malabsorption = Damage to epithelial layer –> contraction (shorter, stunted, blunted) –> less surface area, less function, ↓absorption/↑leakage of bacteria/toxins, etc
Maldigestion = Lack of enzymes and bile results in little to no breakdown of large molecules Water drawn in due to ↑osmotic pressure in intestinal lumen (diarrhea)
What are the clinical signs of intestinal dysfunction? How do these signs typically present?
Abdominal Pain (Colic in large animals)
Vomiting
Diarrhea - Acute or Chronic +/- weight loss/ascites
Constipation
May be present together or as part of systemic condition
What is the difference between volvulus and torsion?
Volvulus is twisting across the short axis (mesenteric axis)
Torsion is twisting along the long axis
How does venous congestion occur?
Thin walled veins get compressed = venous congestion
What is the highest risk associated with ischemic infarction?
Necrosis
Volvulus
Congestion
Describe presentation of upper intestinal tract obstruction
Presentation usually acute and severe
Fluid/gas above obstruction
Vomiting
Metabolic alkalosis (loss of acid in vomitus)
Dehydration
Reduced renal flow and resultant uremia
Describe presentation of lower intestinal tract obstruction - Is it more or less acute than upper intestinal tract obstruction?
Less acute than upper intestinal tract
Still allows function of intestinal tract above obstruction
Increase in fluid resorption proximal to obstruction - Decreased vomiting
Eventual metabolic acidosis due to dehydration and catabolism of fat/muscle (producing keto acids)
Animal no longer receiving nutrients from digestion, breaking down muscle/fat instead (ketoacidosis)
Intussusception
External obstruction - pedunculated lipoma
Explain how neoplasia can create an external obstruction in the intestines
Portion of mesentery grows benign fat-filled tumor (pedunculated lipoma) and is slightly mobile within abdominal cavity
Wraps around gut, causes strangulation effect
What are the clinical signs associated with strangulating lipoma?
Leads to colic signs
Can lead to necrosis/rupture
What role does fibrin have? What does it cause in the abdominal cavity?
Part of clotting/inflammatory cascade
Coats abdominal cavity and organs and leads to fibrinous peritonitis
Noted on PME
Fibrin
What are the 4 basic mechanisms of the pathogenesis of diarrhea?
Do these mechanisms occur in SI, LI or both?
- Malabsorption
- Altered structure/permeability - Secretory Diarrhea
- Altered epithelial cell transport - Maldigestion
- Osmotic effects - Altered Motility
Work in both SI and LI
Give viral causes of diarrhea
Rotavirus
Coronavirus
Parvovirus
Give bacterial causes of diarrhea
Campylobacter
Salmonella
Clostridium (perfringens type A, difficile)