Investigating Canine and Feline Liver Disease Flashcards
List functions of liver
Metabolism carbohydrates
Drug metabolism and excretion
Production of urea from ammonia
Production of coagulation factor
Production of albumin
Immune functions
Metabolism of lipids
Storage of minerals (Fe, Cu, Vitamins)
Bile acid synthesis
Liver failure does not develop until >…? functional capacity is lost
70
List some Causes of Secondary Hepatopathies
Hypoxia / hypotension
Congestion
Non hepatic inflammatory diseases
Drugs
Metastatic Neoplasia
Endocrinopathies
List hypoxic/hypotension causes of secondary hepatopathy
Shock
Surgery
Seizures
Anaemia
List cardiogenic Congestion causes of secondary hepatopathy
Right-sided CHF
Pericardial effusion
List Non hepatic inflammatory diseases causes of secondary hepatopathy
GI disease
Pancreatitis
Sepsis
Toxaemia
List iatrogenic causes of secondary hepatopathy
Glucocorticoids
Phenobarbital
List Endocrinopathies causes of secondary hepatopathy
Hyperadrenocorticism
Hypoadrenocorticism
Diabetes mellitus
Hyperthyroidism (cats)
Hypothyroidism (dogs)
Hyperlipidaemia (Min. Schnauzers)
Breeds predisposed to chronic hepatitis
Springer spaniel
Doberman
Cocker spaniel
Labrador
Breeds predisposed to copper storage disease
Bedlington terriers
Labradors
Breeds predisposed to Gall bladder mucoceles
Shetland Sheepdogs, Border Terriers
Feline hepatic lipidosis risk factors/history
Overweight cats with recent history of anorexia
Hepatotoxic drugs
NSAIDs (Carprofen)
Paracetamol (cats)
Azathioprine
TMPS antibiotics (dogs)
Diazepam (oral, cats)
Lomustine
Carbimazole/methimazole
Phenobarbitone
Infectious causes of acute hepatic disease
CAV-1
Leptospirosis
Clostridium
Acute neutrophilic cholangitis/cholangiohepatitis
Metabolic causes of acute hepatic disease
Hepatic lipidosis (cats)
Toxic causes of acute hepatic disease
Xylitol (chewing gum)
Mycotoxins, aflatoxicosis
Amanita mushrooms
Cyanobacteria- microcystin toxicosis (blue green algae)
Sago palm
Biochemistry of Indicators of liver damage
Liver enzymes – ALT, AST
Biochemistry of Indicators of cholestasis
Liver enzymes – ALP, GGT
Bilirubin
Bile acids
Indicators of liver function
Bile acids
Ammonia
Bilirubin
Glucose, urea, albumin, cholesterol, fibrinogen
ALT
Liver specific enzyme
Alanine AminoTransferase
AST
Liver enzyme
Aspartate aminotransferase (AST)
Liver, skeletal muscle, cardiac myocytes and kidneys
ALP or ALKP
Alkaline phosphatase
GGT
Gamma glutamyl transferase (GGT)
…? is least specific of all markers
ALP
Summarise how billirubin is produced in the body
erythrocytes Transported to the liver and conjugated, secreted into bile, stored in gall bladder and excreted via ducts
How to classify jaundice?
Prehepatic
- Haemolysis
- Increased production exceeds capacity of hepatic excretion
Hepatic
- Abnormal uptake, defective conjugation or abnormal excretion of bilirubin by hepatocytes
Post hepatic
- Impaired excretion of bilirubin
Investigating Pre hepatic Jaundice
Increased PCV
Investigating Post hepatic Jaundice
ALP, GGT > ALT, AST
Hypercholesterolaemia?
Ultrasound biliary system - Assess for obstruction of bile duct, GB rupture
Pancreatic assessment- cPLI
Investigating Hepatic Jaundice
Rule out pre and post hepatic aetiology
Consider biopsy
Cause of Hypocholesterolaemia
Liver failure
Cause of Hypercholesterolaemia
Extrahepatic bile duct obstruction
Intrahepatic cholestatic diseases
Marked hepatic regeneration
How is cholesterol excreted
Derived from diet and made in the liver
Undergoes enterohepatic recycling
Bile provides the major excretory pathway
Will urea levels increase or decrease in liver failure
Decreases with severe liver dysfunction due to failure to convert ammonia to urea
Will glucose levels increase or decrease in liver failure
Occasionally hypoglycaemia seen with severe hepatic compromise (<30% hepatic function)
Most specific test of liver dysfunction are …?
bile acids
Contraindications of Bile acid stim test
Jaundiced
Describe the anemia that could be seen in liver failure
Mild anaemia
Microcytic, hypochromic anaemia with portosystemic shunts
Ascites
Accumulation of free fluid within the abdominal cavity
Causes of ascites
Decreased oncotic pressure- Hypoalbuminaemia
Increased hydrostatic pressure - Portal Hypertension
Leakage from organs (bile)
Inflammation (peritonitis)
Leakage from vessels (blood)
Size of needle used for FNA for liver
23
Pros of FNA
Minimally invasive procedure
Little equipment
Sedation
Useful for lymphoma, mast cell tumours and hepatic lipidosis
Bile samples
Cons of FNA
Accuracy of cytology limited (30-50% agreement with histology)
Does not evaluate hepatic architecture
Only cytology
Iatrogenic damage gall bladder
Name of needle used for Percutaneous biopsy
Cutting Needle (Tru-Cut)
Pros of Biopsy: Cutting Needle
Larger sample size allows examination of hepatic architecture
Avoids laparotomy
Sample focal disease
Cons of Biopsy: Cutting Needle
General anaesthesia
Specialist equipment
Less accurate than surgical biopsies
Difficult with small livers or ascites
Haemorrhage
Pros of Biopsy: Surgical
Better diagnostic samples. Larger sample size allows better examination of hepatic architecture
Can get samples form multiple liver lobes and bile aspirate
Can visualise haemorrhage
Cons of Biopsy: Surgical
General anaesthesia
More invasive procedure
Risks of haemorrhage
List hepatic disease
Chronic Hepatitis
Cholangitis
- Neutrophilic Cholangitis
- Lymphocytic Cholangitis
- Vacuolar Hepatopathies
Hepatobiliary Neoplasia
What is Chronic Hepatitis
Inflammation of the hepatic parenchyma
Often present later stages of chronic hepatitis
Treat with immunosuppressives
What is Cholangitis
Inflammation of the biliary duct
More common in cats +/- duodenitis, pancreatitis, cholangitis (“triaditis”)
What is Neutrophilic Cholangitis
Suppurative inflammation on histology
Ascending infection from intestines – anatomical problem in cats
Treat with AB
What is Lymphocytic Cholangitis
Suspected immune mediated disease
Chronic history of vague illness
Systemically well – normothermic
Treat with immunosuppressive
What is Vacuolar Hepatopathies
Histopathology diagnosis
Hepatocytes become markedly distended with cytosolic glycogen
Associated with glucocorticoid excess:
- Glucocorticoid administration
- Hyperadrenocorticism
Endogenous release of corticosteroids in response to chronic stress, illness, inflammation or neoplasia
ALP often increased (dogs)
What is Gall Bladder Mucocele
Distention of gallbladder by an inappropriate accumulation of mucus
U/S apperance of gall bladder with gall bladder mucocele
“Kiwi” appearance
What is Bile Peritonitis
Inflammatory response of the lining of the abdominal cavity to the presence of free bile
