Deck 5

Question 1

Characterise & name 3 causes of hepatic encephalopathy

Answer 1

Hepatic encephalopathy -> a neuropsychiatric syndrome characterised by augmented neural inhibition. It can develop in animals afflicted with severe acquired liver disease and/or systemic shunting.

Causes: - GIT bleeding
- Increased dietary protein intake
- Increased catabolic rate due to infections
- Constipation

Question 2

Porto-systemic shunting : causes & consequences

Answer 2

Porto-sytemic shunting (Hepatic shunting) -> bypass of the congested liver vessels & returning to the inferior vena cava via alternative routes due to portal hypertension.

Causes: (same as for portal hypertension, since portal hypertension causes hepatic shunting).

-Posthepatic causes (obstruction at the level of the hepatic vein tributaries, cardiac causes, pericardial causes, pulmonary outflow causes)
- Hepatic causes (reduction of sinusoidal flow, collagenisation of the sinusoids, cirrhosis)
- Prehepatic causes (restricted blood flow into or through the portal vein)

Consequences -> coagulation defects
- increased risk of hepatic encephalopathy
- hypoalbuminemia (leading to ascites)
- increased tendency for bleeding

Question 3

Name 2 examples of altered hormone clearance in liver disease & their consequences

Answer 3

1. Decreased inactivation of the small amounts of oestrogen, leading to increased oestrogen in blood
   * Consequence = gynecomastia, feminisation of male, altered protein synthesis, gonadal & pituitary suppression
2. Deceased progesterone inactivation in dairy cows
   (w/severe fatty liver) in postpartum period, leads to
   prolonged progesterone effect
   * Consequence = anoestrus

Question 4

Hepatic encephalopathy: - definition
- 2 mechanisms of disease
- 3 consequences

Answer 4

Hepatic encephalopathy -> neuropsychiatric syndrome characterised by augmented neural inhibition.
It can develop in animals afflicted w/severe acquired liver disease and/or systemic shunting.

2 mechanisms of disease:
- Decreased hepatic function to degrade/eliminate toxins (leading to increased accum. of toxins)
- Increased toxin production
- Altered blood brain barrier

Consequences: - mild confusion
- apathy
- agitation
- euphoria
- restlessness
- reversal of day/night sleep pattern
- severe coma

Question 5

Systemic effects of diarrhoea

Answer 5

• Arrhythmias
• Muscular weakness
• Hypoxia
• Hypoglycaemia