Liver disease 1

Question 1

Describe the structure of the liver

Answer 1

• Made up of lobes with a lobular structure
• Corners of the lobules = portal triads = hepatic artery, portal vein, and bile duct
• Hepatic vein lies in the centre of the lobule

Question 2

Most of the blood comes to the liver via which vessel?

Answer 2

Portal vein
Also some from hepatic artery

Question 3

Where does blood in the portal vein come from?

Answer 3

GIT - detoxification

Question 4

List the hepatic functions

Answer 4

Intermediate metabolism
Storage
Protein synthesis
Production of bile
Detoxification

Question 5

What are the consequences of hepatic dysfunction

Answer 5

Consequences on:
- Bile production
- Metabolic
- Circulation
- Detoxification
- Coagulation

Question 6

Icterus is another name for..?

Answer 6

Jaundice

Question 7

Bilirubin is a breakdown product of …?

Answer 7

RBCs

Question 8

How is the liver involved in bilirubin?

Answer 8

Livers role is to remove bilirubin

Question 9

How can hepatic and post-hepatic icterus be differentiated from pre-hepatic?

Answer 9

MM colour
Pink and yellow jaundice = Hepatic and post-hepatic
Pale yellow on CRT

Question 10

What is the cause of pre-hepatic jaundice?

Answer 10

Haemolysis
Rapid break down of RBCs means there’s more bilirubin present than can be broken down by the liver

Question 11

What is the cause of hepatic jaundice?

Answer 11

Hepatocyte dysfunction
Intrahepatic cholestasis – obstruction of bile flow

Question 12

What is the cause of post-hepatic jaundice?

Answer 12

Extra-hepatic cholestasis
If something is obstructing the bile ducts

Question 13

What are the signs of metabolic dysfunction due to liver disease

Answer 13

• Loss of condition
• Weight loss
• Hypoglycaemia
• Hypoalbuminaemia: only in chronic disease, can contribute to ascites

Question 14

List the 3 circulatory disturbances seen in ascites

Answer 14

Hypoalbuminaemia
Portal hypertension
Sodium and water retention

Question 15

Name the other circulatory disturbances that can occur due to liver disease

Answer 15

Polyuria/polydipsia - cannot concentrate urine maximally
Portosystemic shunts

Question 16

Describe how portosystemic shunts result occur as a consequence of liver disease

Answer 16

Congenital (single) or Acquired (multiple)
Cirrhosis
Portal hypertension – increased pressure in the portal system

Question 17

What are the consequences of portosystemic shunts in the liver?

Answer 17

Lead to a build up of toxins in the liver which would normally be eliminated, particularly ammonia

Question 18

A build up of ammonia leads to which condition?

Answer 18

Hepatic encephalopathy

Question 19

What are the two causes of hepatic encephalopathy

Answer 19

Decreased functional liver mass
and/or
Portosystemic shunt

Question 20

Describe the aetiology of hepatic encephalopathy

Answer 20

Increased blood NH3 (plus other toxins)
Leads to altered CNS function

Question 21

List the clinical signs of hepatic encephalopathy

Answer 21

Anorexia, V & D, PU/PD
Dullness, aggression, staggering, blindness, head-pressing, seizures
Copper coloured irises in cats

Question 22

When are the clinical signs of hepatic encephalopathy worsened?

Answer 22

• High protein meal
• Gastrointestinal bleed
• Dehydration, acid-base imbalance

Question 23

Why does bleeding occur as a result of liver disease?

Answer 23

• Defective production and storage of clotting factors
• Vitamin K malabsorption
• Portal hypertension -> GI bleeding

Question 24

List the main clinical signs of liver disease

Answer 24

• Icterus
• Faecal changes: grey, melaena
• Hepatic encephalopathy
• Drug intolerance
• Ascites
• Stunted growth (if young)
• V + D
• PU/PD
• Anorexia, weight loss, weakness

Question 25

How are hepatopathies classified?

Answer 25

Primary - Inflammatory diseases: Infectious, Non-infectious - Non-inflammatory diseases: Non-infectious Secondary

Question 26

Describe the features of secondary hepatic disease

Answer 26

Non-specific & reversible liver changes - Anoxia - Toxaemia - Nutritional imbalance - Metabolic changes - Infection

Question 27

Name the most common liver abnormality

Answer 27

Reactive hepatopathies

Question 28

How are reactive hepatopathies treated?

Answer 28

By treating the underlying disease

Question 29

Name some examples of reactive hepatopathies

Answer 29

IBD Bacterial infections Periodontal disease Acute pancreatitis Diabetes mellitus Hyperadrenocorticism Hypoadrenocorticism Hyperthyroidism Haemolytic anaemia Septicaemia Shock Right sided HF

Question 30

List some infectious inflammatory causes of hepatopathies

Answer 30

1. Bacterial - Leptospirosis - Bacterial cholangiohepatitis 2. Viral - Infectious canine hepatitis - Canine Herpes virus - FIP 3. Protozoal - Toxoplasma

Question 31

List some non-infectious inflammatory causes of hepatopathies

Answer 31

- Toxic hepatic disease - Drug-induced hepatic disease - All forms of chronic hepatitis

Question 32

List some non-inflammatory causes of hepatopathies

Answer 32

Congenital portosystemic shunt Juvenile hepatic fibrosis Feline hepatic lipidosis Neoplasia Telangiectasis and Peliosis Surgical - Trauma, Liver lobe torsion

Question 33

Feline hepatic idiosyncrasies is caused by?

Answer 33

Relative deficiency of glucuronyl transferase - Difficulty in conjugating toxins

Question 34

Feline hepatic idiosyncrasies is the reason cats are susceptible to which substances?

Answer 34

Aspirin Paracetamol Phenols, pine tars, morphine, benzenes, alcohols, barbiturates

Question 35

Describe paracetamol toxicity in cats

Answer 35

- Relative deficiency of glucuronidation - Relative deficiency of glutathione conjugation - Methaemoglobinaemia - Haemolytic anaemia - Facial oedema - Hepatocellular damage

Question 36

How is paracetamol toxicity in cats treated?

Answer 36

N-acetylcysteine S-adenosyl methionine? Vitamin C Supportive care

Question 37

Describe the clinical signs of liver disease in cats

Answer 37

- Anorexia and weight loss most common - Icterus relatively common - Polyuria / polydipsia - less severe - Hepatoencephalopathy, increased hypersalivation - Microhepatica & cirrhosis rarely seen - Pyrexia common in suppurative cholangitis - Chorioretinitis or uveitis (FIP, toxoplasmosis)