Liver disease and hyperlipidaemia

Question 1

what are the functions of the liver?

Answer 1

digestive/secretory/metabolic
detoxification/excretion
synthetic (clotting factors/proteins)
storage (vitamins/minerals)

Question 2

what are some possible signs of liver disease?

Answer 2

jaundice
weight loss/inappetence
depression/CNS signs
skin lesions
haemorrhage
colic
oedema
diarrhoea
bilateral laryngeal paralysis

Question 3

what is jaundice?

Answer 3

retention of bilirubin (mainly unconjugated)

Question 4

what are some differentials for jaundice?

Answer 4

anorexia
haemolysis
liver failure

Question 5

what are some possible CNS signs that can present with liver disease?

Answer 5

quiet/dull
yawning
progression to somnolence, blindness, head pressing, compulsive walking

Question 6

what are some skin lesions associated with liver disease?

Answer 6

photosensitisation
pruritus
coronitis

Question 7

why does liver disease causes hepatic photosensitisation?

Answer 7

phylloerythrin accumulation as the liver doesn’t remove it, this is activated by UV light

Question 8

what is the cause of pruritus associated with liver disease?

Answer 8

accumulation of bile acids

Question 9

why may liver disease cause haemorrhage?

Answer 9

decreased production of clotting factors

Question 10

why can liver disease cause colic?

Answer 10

hepatitis leads to stretching of the liver which is painful

Question 11

why is laryngeal paralysis one of the first neuropathies seen with liver disease cases?

Answer 11

recurrent laryngeal nerve is very long so any toxins which effect axons will cause damage to this one first

Question 12

what do liver enzyme tests tell us about?

Answer 12

liver damage (released when liver cells are damaged/break open)

Question 13

what liver enzymes are of biliary origin?

Answer 13

GGT and ALP

Question 14

what liver enzymes of of hepatocellular origin?

Answer 14

SDH, GLDH, AST, LDH

Question 15

which liver enzymes are liver specific?

Answer 15

GGT, SDH, GLDH

Question 16

what is a non-liver source of AST?

Answer 16

muscle

Question 17

which enzyme is the most sensitive indicator of liver damage?

Answer 17

GGT

Question 18

what form of liver disease can raised GGT and ALP indicate?

Answer 18

biliary

Question 19

what form of liver disease does raised AST, GLDH and LDH indicate?

Answer 19

hepatocellular

Question 20

how does the degree of increase of liver enzymes correlate with the prognosis?

Answer 20

very poorly correlated

Question 21

why does there need to be significant liver damage before function is impaired?

Answer 21

has a 70% reserve capacity and the ability to regenerate

Question 22

what is the most useful test in horses to assess liver function?

Answer 22

bile acids

Question 23

what is the function of bile acids?

Answer 23

absorb lipids and lipid soluble vitamins
excretion of cholesterol

Question 24

what happens to most of the bile acids secreted by the liver?

Answer 24

reabsorbed in the small intestine and returns via the enterohepatic circulation

Question 25

what happens to bile acids if the liver begins to fail?

Answer 25

they are not reabsorbed after returning through the enterohepatic circulation from the small intestines

Question 26

what are the forms bilirubin can be measured in?

Answer 26

total, conjugated, unconjugated

Question 27

what are the possible differential for increased unconjugated bilirubin?

Answer 27

liver failure, haemolysis, anorexia, intestinal obstruction

Question 28

where does unconjugated bilirubin come from?

Answer 28

breakdown of haemoglobin/myoglobin from macrophages

Question 29

what is the job of the liver in relation to unconjugated bilirubin?

Answer 29

conjugate it and secrete it into the intestines

Question 30

what does a very marked increase in conjugated bilirubin suggest?

Answer 30

choleostasis

Question 31

what form of bilirubin can be found in urine?

Answer 31

conjugated (unconjugated is water soluble)

Question 32

what does the presence of conjugated bilirubin in the urine suggest?

Answer 32

increased systemic levels of bilirubin (possible cholestasis or liver failure)

Question 33

what are some tests for liver function?

Answer 33

bile acids bilirubin ammonia

Question 34

why is ammonia difficult to measure?

Answer 34

very volatile so have to test the blood very soon after taking the sample RBCs also produce it which will change the concentration in the sample

Question 35

what is ammonia turned into in the liver?

Answer 35

urea

Question 36

how will urea concentration change if the liver has decreased function?

Answer 36

decrease (lack of ammonia metabolism)

Question 37

how will globulin concentration change if the liver has decreased function?

Answer 37

increase (kupffer cells failure to remove intestinal antigens)

Question 38

how will triglyceride concentration change if the liver has decreased function?

Answer 38

increase (inadequate carbohydrate metabolism and gluconeogenesis)

Question 39

how should the liver appear compared to the spleen?

Answer 39

slightly hypoechoic to the spleen

Question 40

what are some possible complications of liver biopsies?

Answer 40

haemorrhage inappropriate sample negative culture infections

Question 41

what are liver biopsies usually used for?

Answer 41

help to give severity and prognosis of a condition guide treatment

Question 42

what toxicity is causes by ragwort?

Answer 42

pyrrolizidine alkaloid toxicity

Question 43

what is the pathogenesis of pyrrolizidine alkaloid toxicity?

Answer 43

alkylates DNA leading anti-mitosis causing megalocytosis as the cells are unable to divide, they then get damaged and die leading to fibrosis

Question 44

how is ragwort usually ingested by the horse?

Answer 44

in hay - more palatable when dried

Question 45

when do horses begin to show clinical signs of ragwort poisoning?

Answer 45

very late in disease process when they have liver failure just prior to death

Question 46

should ragwort poisoning be treated?

Answer 46

depends on severity of clinical signs (mainly supportive)

Question 47

what is chronic active hepatitis?

Answer 47

any progressive inflammatory hepatitis

Question 48

what should always be included in the treatment for chronic active hepatitis?

Answer 48

corticosteroids - immunosuppressive

Question 49

how should hepatic encephalopathy be treated?

Answer 49

reduce neurotoxin production - metronidazole, lactulose avoid sedation fluid balance and regulate glucose

Question 50

how can metronidazole be used to treat hepatic encephalopathy?

Answer 50

reduces the number of ammonia producing bacteria

Question 51

how does lactulose aid treatment of hepatic encephalopathy?

Answer 51

poorly digested/absorbed carbohydrate which will increase the acidity of the colon (increasing H+) to convert ammonia into ammonium

Question 52

how will a blood sample of hyperlipaemia appear?

Answer 52

fatty serum (dense white cloudy)

Question 53

what are some risk factors for hyperlipaemia?

Answer 53

breed obesity females insulin sensitivity transport, stress, lactation starvation

Question 54

what is the pathogenesis of hyperlipaemia?

Answer 54

stored fats are broken down and fatty acids are taken to the liver to produce energy which leads to triglycerides accumulating in the liver and plasma

Question 55

what equine in very susceptible to hyperlipaemia?

Answer 55

donkeys

Question 56

how does hyperlipaemia present?

Answer 56

anorexia, lethargy, weakness (non-specific)

Question 57

how is hyperlipaemia treated?

Answer 57

get animal in positive energy balance (tube feed) correct dehydration and acidosis symptomatic therapy

Question 58

what is the prognosis for hyperlipaemia?

Answer 58

guarded to poor