Intestinal Pathology Flashcards
What are the clinical signs of intestinal dysfunction?
Abdo pain, colic
Vomiting
Diarrhoea
Constipation
What causes abdo pain?
Volvulus
Torsion
Obstruction
Rupture
Name 4 internal gastro obstruction….
FB
Parasites
Tumour
Intussusception
Give an example of an external gastro obstruction…
Strangulating lipoma
How do upper and lower GI obstruction differ?
Upper - Acute and severe vomiting leads to metabolic alkalosis, dehydration and reduced renal flow (uraemia)
Lower - Less acute, pressure leads to ulceration, infarction, haemorrhage, peritonitis, dehydration and muscle catabolism leading to metabolic acidosis
What causes fibrin in the peritoneal cavity?
Inflammation
What are the four mechanisms for diarrhoea?
- Altered structure/permeability
- Altered epithelial cell transport
- Osmotic effects
- Altered motility
What can the loss of water and ions cause during acute diarrhoea?
Water:
Dehydration
Haemoconcentration
Hypovolaemic shock
Ions:
Hypokalaemia
Metabolic acidosis
Which ions are lost in acute D+?
Sodium
Potassium
Bicarbonate
What can broadly cause acute diarrhoea?
Viruses
Bacteria
Endoparasites
Protozoa
What viruses cause acute diarrhoea?
Rotavirus
Parvovirus
What bacteria can cause acute diarrhoea?
Campylobacter
Salmonella
Clostridium
What protozoa can cause acute diarrhoea?
Cryptosoridum
Coccidium
On histology, how can you tell the infectious disease of diarrhoea is salmonella?
Causes severe focal mucosal damage overlying submucosal lymphoid tissue.
What is colitis X in horses?
Clostridial colitis
On gross PM examination, how can you tell a horse’s diarrhoea is due to Clostridum?
The mucosa has been colonised extensively and soluble toxins have been released showing balck.
What can cause chronic diarrhoea +/- weight loss?
IBD Lymphangiectasia Endoparasites Neoplasia Grass sickness
What are the two subdivisions of IBD?
Eosinophillic
Lymphoplasmacytic
How can intestinal bacterial overgrowth occur?
Increased entry of bacteria
Increased multiplication of bacteria
Reduced clearance of bacteria
Outline the pathophysiology of bacterial overgrowth in the gut…
Bacterial overgrowth > Bile salt deconjugation, toxins, consumption of nutrients > bile salt deficiency and epithelial damage > Malabsorption
What occurs during PLE?
- Increased permeability to plasma proteins > lost in intestinal lumen
- Chronic inflammation > lymphatic blockage
Outline the pathophysiology of PLE…
Albumin loss exceeds liver synthesis > Hypoalbuminaemia > Decreased plasma oncotic pressure > Oedema and ascites
How can endoparaites reduce intestinal function?
Malabsorption
Obstruction
Vascular compromise
Which parasite can compromise the vascularity of the intestine in horses?
Strongylus vulgaris
