Intestinal Pathology

Question 1

What are the clinical signs of intestinal dysfunction?

Answer 1

Abdo pain, colic
Vomiting
Diarrhoea
Constipation

Question 2

What causes abdo pain?

Answer 2

Volvulus
Torsion
Obstruction
Rupture

Question 3

Name 4 internal gastro obstruction….

Answer 3

FB
Parasites
Tumour
Intussusception

Question 4

Give an example of an external gastro obstruction…

Answer 4

Strangulating lipoma

Question 5

How do upper and lower GI obstruction differ?

Answer 5

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

Question 6

What causes fibrin in the peritoneal cavity?

Answer 6

Inflammation

Question 7

What are the four mechanisms for diarrhoea?

Answer 7

• Altered structure/permeability
• Altered epithelial cell transport
• Osmotic effects
• Altered motility

Question 8

What can the loss of water and ions cause during acute diarrhoea?

Answer 8

Water:
Dehydration
Haemoconcentration
Hypovolaemic shock

Ions:
Hypokalaemia
Metabolic acidosis

Question 9

Which ions are lost in acute D+?

Answer 9

Sodium
Potassium
Bicarbonate

Question 10

What can broadly cause acute diarrhoea?

Answer 10

Viruses
Bacteria
Endoparasites
Protozoa

Question 11

What viruses cause acute diarrhoea?

Answer 11

Rotavirus

Parvovirus

Question 12

What bacteria can cause acute diarrhoea?

Answer 12

Campylobacter
Salmonella
Clostridium

Question 13

What protozoa can cause acute diarrhoea?

Answer 13

Cryptosoridum

Coccidium

Question 14

On histology, how can you tell the infectious disease of diarrhoea is salmonella?

Answer 14

Causes severe focal mucosal damage overlying submucosal lymphoid tissue.

Question 15

What is colitis X in horses?

Answer 15

Clostridial colitis

Question 16

On gross PM examination, how can you tell a horse’s diarrhoea is due to Clostridum?

Answer 16

The mucosa has been colonised extensively and soluble toxins have been released showing balck.

Question 17

What can cause chronic diarrhoea +/- weight loss?

Answer 17

IBD
Lymphangiectasia
Endoparasites
Neoplasia
Grass sickness

Question 18

What are the two subdivisions of IBD?

Answer 18

Eosinophillic

Lymphoplasmacytic

Question 19

How can intestinal bacterial overgrowth occur?

Answer 19

Increased entry of bacteria
Increased multiplication of bacteria
Reduced clearance of bacteria

Question 20

Outline the pathophysiology of bacterial overgrowth in the gut…

Answer 20

Bacterial overgrowth > Bile salt deconjugation, toxins, consumption of nutrients > bile salt deficiency and epithelial damage > Malabsorption

Question 21

What occurs during PLE?

Answer 21

• Increased permeability to plasma proteins > lost in intestinal lumen
• Chronic inflammation > lymphatic blockage

Question 22

Outline the pathophysiology of PLE…

Answer 22

Albumin loss exceeds liver synthesis > Hypoalbuminaemia > Decreased plasma oncotic pressure > Oedema and ascites

Question 23

How can endoparaites reduce intestinal function?

Answer 23

Malabsorption
Obstruction
Vascular compromise

Question 24

Which parasite can compromise the vascularity of the intestine in horses?

Answer 24

Strongylus vulgaris

Question 25

What are the clinical signs of acute grass sickness?

Answer 25

Damaged neurons
Nasogastric reflux and oesophageal ulceration
Gastric dilation and rupture

Question 26

What are the clinical signs of cubacute/crhonic grass sickness?

Answer 26

Weight loss
Muscle tremors
Rhinitis sicca
Dysphagia
Patchy sweating
Constipation
Large  colon impaction

Question 27

What post-mortem finding is consistent with grass sickness?

Answer 27

Impacted large colon