General Medicine Liver

Front 1

What is the main blood supply of the liver?

Back 1

Arterial: from *hepatic a.
Venous: from SI via *portal v.
Converge in sinusoids and exit into central veins, central veins drain into hepatic vein

Front 2

What cell in the liver are responsible for clearing foreign substances, antigens, bacteria and aged red blood cells?

Back 2

Kupffer cells

Front 3

There is increased ______ production with Kupffer cell dysfunction.

Back 3

IgM-because get immune stimulation

Front 4

What do you see on serum protein electrophoresis when there's chronic liver disease?

Back 4

Beta-gamma bridging

Front 5

Explain the flow of bile.

Back 5

Bile--> canaliculi & bile ducts--> cystic duct and gall bladder ---> common bile duct---> SI

Front 6

What animals lack a gallbladder?

Back 6

Horses & camelids

Front 7

What is enterohepatic cycling?

Back 7

Substance excreted in bile is resorbed and recirculates in portal blood to the liver

Front 8

What can you use to detect issues in enterohepatic cycling?

Back 8

-bile acids (extensive- so if increased means issues w/ enterohepatic cycling)
-bilirubin & urobilinogen

Front 9

What is the reserve capacity of the liver?

Back 9

60-75%, excellent capacity for regeneration and reserve
-so when signs then large loss of function

Front 10

What are 6 functions of the liver?

Back 10

1) Carbohydrate metabolism
2) Protein metabolism
-binding proteins, coagulation factors, lipoproteins
3) Fat metabolism
-FA and ketone synthesis
4) Urea synthesis
5) Bile acid synthesis
6) Detoxification
-bilirubin, urea, aromatic amino acids

Front 11

What happens to urea and ammonia levels with liver disease?

Back 11

Decreased BUN, increased ammonia

Front 12

Does hypoglycemia indicates acute or chronic liver disease?

Back 12

Acute

Front 13

What is bilirubin derived from?

Back 13

hemoglobin (80%) and non-Hb hemoprotein
-Heme--> biliverdin--> unconjugated bilirubin

Front 14

What happens to unconjugated bilirubin from heme breakdown?

Back 14

UCB enters liver--> water soluble conjugated bilirubin (glucuronyl transferase)

Front 15

Explain the colors associated with bruising.

Back 15

Heme=red------>
Biliverdin= green---->
UB=yellow

Front 16

What does it mean if there's no urobilinogen in the urine?

Back 16

Means there's a bile duct obstruction e.g. common bile duct obstruction

Front 17

What happens to conjugated bilirubin?

Back 17

-Excreted into canaliculi (small amount enters blood)
-CB converted to urobilinogen in bowel
-some urobilinogen undergoes EH cycling, some enters urine

Front 18

What are 4 causes of hyperbilirubinemia?

Back 18

1) Excess production
-hemolysis
2) Hepatocellular disease
-decreased uptake into hepatocytes--> disturbed conjugation
3) Disturbed secretion of CB
-intra or extra hepatic bile obstruction
4) Congenital syndromes (sheep)

Front 19

What are 2 causes of an increased fraction of unconjugated bilirubin?

Back 19

Hemolysis
Hepatocellular disease

Front 20

What does an increase in conjugated bilirubin indicate?

Back 20

Obstructive biliary disease

Front 21

How do you different the cause of hyperbilirubinemia? (3)

Back 21

1) Clinical findings- hisotry & PE
2) Lab findings
-CBC, chem panel, SBA
3) Diagnostic tests

Front 22

What are 8 clinical findings of hemolytic disease?

Back 22

1) icterus
2) anemia (pale membranes)
3) Weakness
4) Elevated HR/RR
5) Hemoglobinuria
6) Water blood w/ pink serum
7) Low PCV, RBC +/- Hb
8) Normal liver enzymes and SBA's

Front 23

How can you tell how severe hemorrhage is without look at respiratory rate or heart rate?

Back 23

Correlate PCV to total protein

Front 24

Do you see icterus with acute liver damage?

Back 24

No, jaundice takes time to develop

Front 25

How do you differentiate b/w myoglobin, hemolgobin and RBCs in urine?

Back 25

Myoglobin: look at serum should be clear and CK elevated
Hemoglobin: serum should be pink
RBCs: spin down urine and if becomes clear with pellet on bottom

Front 26

*What are 5 infectious causes of hemolytic anemia in horses?

Back 26

1) Leptospirosis
2) Babesiosis
3) Eperythrozoon
4) Equine infectious anemia
5)*Clostridium toxins

Front 27

What are 2 toxic causes of hemolytic anemia?

Back 27

1) Copper
2) Toxic plants
-red maple, onion, brassica, kale, rape

Front 28

What are 3 immune mediated causes of hemolytic anemia?

Back 28

1) AIHA
2) Neonatal isoerythrolysis
3) Incompatible blood transfusion

Front 29

What are 5 causes of hepatocellular failure?

Back 29

1) Toxins
-pyrrolizidine alkaloids
2) Immune mediated
3) Hypoxia, toxemia, and shock
4) Infectious diseases
5) Lipidosis

Front 30

What are 8 causes of obstructive hepatic disease?

Back 30

1) Cholangitis
2) Cholangiohepatitis
3) Fibrosis
4) Cholelithiasis
5) Parasites
6) Hepatic abscesses
7) Neoplasia (all spp)
8) Pancreatitis (dogs)

Front 31

What type of bilirubin causes bilirubinuria?

Back 31

CB= soluble bilirubin

Front 32

What are 5 clinical findings of obstructive disease? (diagnostics)

Back 32

1) Increased serum CB fraction
2) Biliary distension on biopsy or ultrasound
3) Bilirubinuria
-excretion increased CB
4) Absence of urine urobilinogen
5) Increased GGT & ALP

Front 33

What are 6 important pieces of history when trying to figure out the cause of hyperbilirubinemia or hemolysis?

Back 33

1) Vaccination or transfusion
2) Potential exposure to plant or chemical toxins
3) Fever, colic, weight loss
4) Number of affected/ exposed in herd
5) Behavioral changes
6) Meds

Front 34

What are 2 signs of severe hepatomegaly on clinical exam?

Back 34

Percussion dullness
Pain caudal to rib cage on R

Front 35

When do clinical signs of liver failure develop?

Back 35

Once ~75% of parenchyma is compromised
-hepatic disease w/o insufficiency shows few signs

Front 36

When is icterus more profound, with acute or chronic liver failure?

Back 36

Acute failure or diseases w/ elevated CB

Front 37

Is icterus common in ruminants?

Back 37

No, so when see it know its very significant

Front 38

How do you differentiate icterus from hemolysis or fasting?

Back 38

By serum color and liver enzymes

Front 39

What are the 9 signs of hepatic failure?

Back 39

1) Icterus
2) Hepatic encephalopathy
3) Weight loss
4) Photosensitization
5) Pruritus
6) Ventral edema & ascites
7) Hemorrhage
8) Diarrhea
9) Abdominal pain

Front 40

What are the signs of hepatic encephalopathy?

Back 40

Depression, head pressing, aimless walking, circling, mild ataxia, persistent yawning
-eventually recumbency & coma
-tenesmus in cattle

Front 41

Why does liver failure cause weight loss?

Back 41

Anorexia, chronic inflammation, altered metabolism
-especially in chronic disease

Front 42

Weight loss due to hepatic failure has to be differentiated form what 5 things?

Back 42

1) parasitism
2) Malnutrition
3) Neoplasia
4) Other organ failure
5) Other causes chronic inflammation

Front 43

Do animals with hepatic encephalopathy have a menace response?

Back 43

No, they don't see you

Front 44

Does photosensitization usually develop with acute or chronic liver failure? How does it occur? Clinical signs?

Back 44

chronic
Accumulation of phylloerythrin in skin + reacts w/ light
Erythemia, crusting and necrosis- lesions of non-pigmented skin

Front 45

Why does edema and ascites develop in animals with liver failure?

Back 45

Hypoalbuminemia
Increased portal pressure from hepatic fibrosis
-ascites in calves and dogs

Front 46

Why is there hemorrhage w/ liver failure?

Back 46

Decreased clotting factors & vit K absorption

Front 47

Why do animals with liver failure sometimes develop diarrhea? Which animals do?

Back 47

Cattle & small animals w/ chronic disease
-portal hypertension, increased hydrostatic pressure in bowel

Front 48

Why can animals with liver failure develop fever?

Back 48

Cholelithiasis, hepatic abscesses

Front 49

Why do animals with liver failure have discolored urine?

Back 49

bilirubinuria

Front 50

What are 2 reasons that hepatocellular and cholestatic disease rarely occur as individual entities?

Back 50

-cellular damage results in cell swelling and secondary occlusion of the biliary tract
-biliary dysfunction causes retention of toxic bile products w/ secondary cellular damage

Front 51

What are leakage enzymes?

Back 51

Concentrated in liver cells and damages increases serum levels

Front 52

What are the 5 hepatic leakage enzymes?

Back 52

1) ALT
2) AST
3) GLDH
4) SDH
5) LDH

Front 53

Do leakage enzymes tell you anything about function?

Back 53

No, poor correlation to damage and function

Front 54

What is ALT? What causes it to increase?

Back 54

Alanine aminotransferase
Hepatic necrosis in primates and small animals

Front 55

What is AST? What cell(s) is it present in?

Back 55

Aspartate aminotransferase
-liver, muscle, RBCs
-interpret with CK

Front 56

What is the specificity and sensitivity of AST for liver disease?

Back 56

Sensitive indicator of hepatocellular disease, but not specific can be liver, muscle or RBCs

Front 57

When does AST peak? Decrease?

Back 57

Peaks in ~24 h
Decreases in 2-3 days

Front 58

What is the best enzyme to detect hepatocellular damage in ruminants?

Back 58

GLDH

Front 59

What is GLDH? When does it Peak? Decrease?

Back 59

Glutamate dehydrogenase
-Peaks in ~24 h
-short half life

Front 60

What is the specificity of SDH? What is SDH?

Back 60

Sorbitol dehydrogenase
-specific for ACUTE hepatocellular damage
-short half life so normalizes rapidly
-increases w/ acute GI obstruction or enteritis in horses

Front 61

What does it mean if there's a continuing increase of SDH?

Back 61

Continuing disease, because short half life so levels normalize rapidly

Front 62

Describe the specificity of LDH?

Back 62

Non-specific unless LDH 5

Front 63

Why isn't SDH measured very often in the field?

Back 63

Very labile, can't keep over night

Front 64

What do induced enzymes indicate?

Back 64

Active biliary tract disease

Front 65

What causes increased induced enzymes?

Back 65

Increased de novo syntehsis:
-drugs: corticosteroids, barbiturates
-Cholestasis

Front 66

Do induced enzymes indicate acute or chronic biliary tract disease?

Back 66

Takes a few days to increase

Front 67

What are the induced liver enzymes?

Back 67

ALP
GGT

Front 68

What contains ALP in the body? What does ALP stand for?

Back 68

Liver, GI and bone isoenzymes
Alkaline phosphatase

Front 69

What liver enzyme is normally elevated in young animals?

Back 69

ALP

Front 70

When do ALP levels peak?

Back 70

5-6 days post insult

Front 71

What can cause a massive increase in ALP? What animal(s) is ALP not useful in/

Back 71

Bile duct obstruction
Ruminants-wide fluctuations

Front 72

GGT serum levels correspond to_________.

Back 72

Cholestasis
-urine GGT used to evaluate renal disease

Front 73

When does GGT peak/

Back 73

~7 days and long half life

Front 74

What enzyme has the highest sensitivity for liver disease in horses?

Back 74

GGT (gamma glutamyltransferase)

Front 75

What liver enzyme can be used to assess passive transfer?

Back 75

GGT
-Serum GGT elevated for first 2 weeks of life
-normal foals commonly have GGT 2 to 3 x normal for 2 weeks

Front 76

What are 4 non-specific tests of liver function?

Back 76

1) Bilirubin
2) Total protein and SEP
3) Urinalysis
4) BuN & glucose

Front 77

What are 4 causes of increased bilirubin?

Back 77

1) fasting
2) hemolysis
3) hepatocellualr and cholestatic liver disease

Front 78

What will you see on a total protein and serum protein electrophoresis of an animal with liver failure?

Back 78

1) Decreased albumin
2) beta-gamma bridging
3) Polyclonal gammopathy

Front 79

What causes bilirubinuria?

Back 79

Obstructive disease

Front 80

What causes increased urine urobilinogen?

Back 80

Hemolysis
Hepatocellular disease

Front 81

What happens to BUN and glucose w/ hepatic failure?

Back 81

Altered production and regulation causes a decrease in both

Front 82

What are 2 specific tests of liver function/

Back 82

1) Serum bile acids
2) Blood ammonia

Front 83

95% of serum bile acids are reabsorbed from ____into the portal vein.

Back 83

Ileum, then 90-95% extracted by liver cells on first pass

Front 84

How does hepatic disease cause an increase in serum bile acids?

Back 84

Decreases extraction and/or causes regurgitation into circulation

Front 85

What are 2 downfalls of serum bile acids for evaluating hepatic disease?

Back 85

1) Low specificity for type or degree of dysfunction
2) not useful in ruminants

Front 86

What does increased blood ammonia usually indicate?

Back 86

Diffuse disease

Front 87

What are 2 causes of increased blood ammonia?

Back 87

1) Hepatic shunts
-failure to detoxify blood
2) Gut associated hyperammonemia

Front 88

Blood ammonia levels remain normal until > ___% of hepatic function is lost.

Back 88

60%

Front 89

How should blood be stored to measure blood ammonia?

Back 89

Very unstable
-ice samples and analyze immediately

Front 90

What can you visualize with ultrasonography of the liver?

Back 90

Hepatic texture & size
Vessels & bile ducts
Specific abnormalities
-biliary distension, choleliths, hepatic tumors, abscesses

Front 91

When are liver biopsies a help diagnostic tool for diagnosing hepatic disease?

Back 91

when diffuse disease

Front 92

What is the purpose of performing ultrasound guided liver biopsies?

Back 92

assists biopsy site selection and avoids large vessels and other structures

Front 93

Do we usually anesthetize animals for liver biopsies?

Back 93

no, we use sedation in all species and standing in large animals

Front 94

What are 6 abnormalities that a liver biopsy may identify?

Back 94

1) Biliary abnormalities
2) Fibrosis
3) Inflammatory cells
4) Neoplasia
5) Necrosis
6) Fat infiltration

Front 95

What is portovenogrpahy good for?

Back 95

Small animals and large animal neonates to identify hepatic shunts

Front 96

When are exploratory laparotomies helpful to diagnose hepatic issues?

Back 96

Suspected portal shunts
Diagnosis of liver disease in cattle

Front 97

Why perform a fecal exam with liver issues/

Back 97

Liver fluke eggs in ruminants

Front 98

What are 6 indicators of a poor prognosis of liver issues?

Back 98

1) Hypoalbuinemia
2) Hyperglobulinemia
3) Prolonged PT
4) High GGT & ALP w/ low or normal SDH
5) Fibrosis
6) HE or hemolytic crisis