Gastro - Icterus

Question 1

What are the causes of icterus?

Answer 1

Pre-hepatic, hepatic, and post-hepatic

Question 2

What causes prehepatic icterus?

Answer 2

Hemolysis - conjugation and uptake of bilirubin into the liver is overwhelmed

Question 3

What is ‘overwhelmed’ with hepatic icterus?

Answer 3

Uptake, conjugation, and excretion of bilirubin in the hepatocytes is overwhelmed

Question 4

What is the cause of post-hepatic icterus?

Answer 4

Cholestasis which causes conjugation, excretion, and uptake back into the liver to be overwhelmed

Question 5

What GI signs can give clues to icterus and liver disease?

Answer 5

Vomiting, diarrhea, acholic feces, melena, and abdominal effusion (ascites)

Question 6

What neurologic signs can give clues to icterus and liver disease?

Answer 6

Personality change, ptyalism (cats), head pressing, disorientation, seizures, and stupor

Question 7

What renal/urinary signs can give clues to icterus and liver disease?

Answer 7

PU/PD, pollakiuria, stranguria, dysuria, and bilirubinuria

Question 8

What could cause pale mucus membranes?

Answer 8

Anemia from GI hemorrhage, anemia of chronic disease, a coagulation disorder, and hemolysis

Question 9

What are the differentials for prehepatic icterus?

Answer 9

Immune hemolytic anemia, babesia infection, mycoplasma hemofelis, cytoxzoon, and toxins such as onions, lead, and copper

Question 10

What are the differential diagnoses for hepatic icterus in cats?

Answer 10

Suppurative cholangiohepatitis
Lymphocytic plasmacytic hepatitis
Hepatic lipidosis
Feline Infectious peritonitis
Toxins (acetaminophen,aspirin)
Neoplasia

Question 11

What are the differential diagnoses for hepatic icterus in dogs?

Answer 11

Acute liver disease (toxins), leptospirosis, chronic hepatitis, and neoplasia

Question 12

What are the differential diagnoses for posthepatic icterus?

Answer 12

Pancreatitis, neoplasia, and cholelithiasis

Question 13

How would you differentiate between prehepatic and hepatic icterus?

Answer 13

Perform a PCV/TS

If prehepatic - PCV is low, TS is normal
If hepatic - PCV is usually normal, TS can be low if albumin is low

Question 14

How would you differentiate between hepatic and post-hepatic icterus?

Answer 14

Imaging:

Ultrasound will identify obstruction of the gall bladder, and masses, or pancreatitis associated with it

Question 15

What diagnostic tests can be done for hepatic diseases?

Answer 15

Bloodwork, UA, abdominal ultrasound, liver function tests, coagulation tests, aspirate effusion and cytology, liver fine needle aspirate, fine needle aspirate and culture of bile, and a liver biopsy

Question 16

What is the most liver specific enzyme?

Answer 16

ALT

Question 17

What liver enzyme is also present in the muscle, intestines, and other organs?

Answer 17

AST

Question 18

What produces the enzyme AP?

Answer 18

biliary duct cells

Question 19

In what species does AP have isoenzymes in? What does this mean?

Answer 19

Dogs
It means that if you give cortisol, the levels of AP will increase, so you need to keep this in mind when looking at chemistry results

Question 20

What are some indications of liver failure on a chemistry profile?

Answer 20

Low albumin, low cholesterol, low glucose, and low BUN

Question 21

Where are bile acids produced?

Answer 21

in the liver from cholesterol

Question 22

After bile acids are produced, where do they go?

Answer 22

Into the enterohepatic circulation and then eventually there is re-uptake from the blood into the hepatocytes

Question 23

How is a bile acids test done?

Answer 23

You take a measurement, give food, and then take another measurement some hours later

Question 24

When are bile acids elevated after a bile acid test?

Answer 24

in liver failure/portosystemic shunt