Clin Path

Question 1

What is jaundice? (icterus)

Answer 1

Yellowing of the skin and other tissues due to deposition of bilirubin

Question 2

What is cholestasis?

Answer 2

Bile w/o motion

Question 3

What is hyperbilirubinemia?

Answer 3

Increased circulating levels of bilirubin in the blood.

• Retention form refers to increases in unconjugated
• Regurgitation form refers to increases in conjugated
• Combined form refers to increases in both

Question 4

WHat is Hepatic encephalopathy?

Answer 4

signs of CN ds related to liver ds. In the dog & cat it is invariable related to congenital or acquired vascular shunting

Question 5

What are acute phase reactants?

Answer 5

refers to altered (mostly increased) levels of specific proteins (mostly globulins) in the blood. They can include clotting proteins e.g. fibrinogen, haptoglobin and C-reactive protein. They occur in response to a variety of acute/active degenerative/inflammatory conditions

Question 6

Biochemical tests, (liver “function” tests) can detect 3 basic processes that can occur in liver
disease

Answer 6

hepatocellular damage, cholestasis and reduced functional mass.

Question 7

T/F: Biochemical tests cannot differentiate primary and secondary hepatic ds.

Answer 7

TRUE

Question 8

Active liver cell damage tests which enzymes?

Answer 8

AST, ALT, LD, ID, ARG, GD, ICD (depending on sp)

Question 9

Cholestasis tests depend on which enzymes?

Answer 9

ALP (ALKP), GGT (both induces enzymes)

Question 10

Cholestasis and cell damage tests use

Answer 10

bilirubin analysis (total; unconjugated; conjugated)

Question 11

Reduced functional hepatic mass is determined by

Answer 11

Bile acids (will detect all 3 processes but more commonly reduced hepatic mass), Bromsulphopthalein (BSP) test ( no longer used, largely replaced by bile acids analysis), blood ammonia/urea, serum proteins

Question 12

For levels of serum enzymes to be elevated in liver ds, an active damaging process to a significant number of hepatocytes is required. Is this more likely acute/sub-acute or chronic?

Answer 12

acute/sub-acute.

Question 13

What liver enzyme would be elevated if there was hepatocellular damage (hepatocyte damage) in a dog/cat?

Answer 13

ALT - also in certain muscle ds in certain breeds (combine with CK). It is present in the cytoplasm, even changes in cell permeability can increase levels.
–> corticosteroids and anti-convulsants may induce ALT

Question 14

What liver enzyme is used to detect hepatocyte damage commonly for the horse but also the dog.

Answer 14

ID - Iditol dehydrogenase

Question 15

What species is the enzyme OCT used in to determine hepatic disease (hepatocyte damage)?

Answer 15

Liver specific in most species. Rarely used except in pigs.

Question 16

what enzyme would you use to determine cholestasis(hepatic ds) in the dog/cat

Answer 16

ALP, lesser so GGT

Question 17

What enzyme would you use to determine in cholestatis (liver ds) was occuring in the horse?

Answer 17

GGT, lesser so ALP.

Question 18

What enzyme would you use to determine is cholestasis(hepatic ds) was occuring in the sheep/cattle/pig?

Answer 18

GGT.

Question 19

What enzymes would show up if there were cardiac/skeletal damage in any species?

Answer 19

CK, AST, KD (esp isoenzyme analysis)

Dogs and cats maybe ALT elevations

Question 20

Which enzyme warrants further investigation in the cat in regards to cholestasis and why?

Answer 20

ALP, irrespective of the magnitude in change as cats have lower levels in hepatocytes and biliary epithelium and shorter plasma T1/2 in the cat (6 hours compared to 72hrs in the dog).

Question 21

What does the Van den Bergh’s test measure?

Answer 21

Serum bilirubin

Question 22

Why might bilirubin levels in the male dog need to be interpreted with care?

Answer 22

THe dog has a low renal threshold to conjugated bilirubin. The male dog’s kidney has good ability to break down haemoglobin and to conjugate bilirubin.

Question 23

Icterus of the tissues due to the presence of significant hyperbilirubinemia has been divided into 3 types:

Answer 23

1. Retention hyperbilirubinemia -> unconjugated bilirubin predominant in the blood (haemolytic crises are the main cause; extrahepatic and hepatic ds can interfere with hepatic uptake and conjugation e.g. anorexia )
2. Regurgitation (cholestatic) hyperbilirubinemia -> conjugated is predominant form. Bilirubinuria is usually present. Both intra and extrahepatic pbstruction to bile flor produce regurgitation hyperbilirubinemia
3. Combined hyperbilirubinemia -> develops both due to retention and regurgitation methods -> both conjugated and unconjudated bilirubin levels in the blood are increased. Bilirubinuria usually present. Can occur in both acute/chronic hepatic ds.

Question 24

How are bile acids synthesised?

Answer 24

by hepatocytes from cholesterol and then conjugated prior to excretion in the bile. Stored and concentated in the gall bladder during the interdigestive period.

Question 25

What is serum protein estimation useful in deterimine?

Answer 25

Serum protein estimation (total and types of protein) can be useful in detecting a chronic
hepatopathy. It is rarely of use in early hepatopathies (but there may be increased levels of
globulins in acute hepatic disease. These increased proteins are usually acute phase reactants.

Question 26

What is significant about cholesterol in determining ds?

Answer 26

Cholesterol is utilised for the synthesis of bile acids. Hypercholesterolemia can occur in
cholestatic conditions but may also occur in the nephrotic syndrome, acute pancreatitis,
congenital hyperlipidemias and certain endocrinopathies (DM, hyperadrenocorticism,
hypothyroidism). Increases may also occur post prandially. Increased blood levels of cholesterol
alone will not cause gross turbidity of the serum or plasma. Decreased serum cholesterol can
occur in hepatic shunting and in gut problems (Exocrine Pancreatic Insufficieancy,
malabsorption, Protein Losing Gastroenteropathy).

Question 27

What is malassimilation?

Answer 27

Collective for maldigestion and malabsorption.

Question 28

What is maldigestion? and malabsorption?

Answer 28

maldigestion = abnormality in the failure of normal digestive processes

malabsoroption = abnormality resulting in the failure of normal absorptive processes

Question 29

What are the types of exocrine pancreatic disorders?

Answer 29

acute pancreatic necrosis (necrotizing pancreatitis) and pancreatic insufficiency.

Question 30

What enzymes can be used to confirm acute bouts of pancreatic necrosis in the dog and other sp. ?

Answer 30

Elevation of serum enzymes. In the dog and cat elevations of AMS and LPS.

along with other supportive lab findings - haematology (stress leuk with left shift); hyperlipidemia (fasting); fluid imbalance (due to emesis and loss of HCl); pre-renal azotemia; non-septic exudate in peritoneal cav; transient, mild hyperglycemia; transient hypocalcemia.

NOTE: Hepatocellular necrosis and cholestasis may occur secondarily to the acute pancreatic
necrosis and need to be investigated appropriately.