Icterus and liver / pancreas disease Flashcards
pancreas enzyme specificity?
amylase and lipase arent very specific
can use CPLI (canine pancreatic lipase) which is specific
What hepatocellular enzymes are used to measure damage to hepatocytes?
ALT - most specific in cats and dogs, can be released from massively damaged muscle
AST - also in muscle and RBC
SDH - used in horse
GLDH
What can you measure to rule out muscle involvement?
Creatinine kinase - increases and decreases faster than ALT and AST
What enzymes are used to measure cholestasis?
ALP - from bile duct ep and increases with cholestasis, there is a steroid induced isoform in dogs, very short half life in cats
GGT - from bile duct ep, used in large animals
How would you expect the measure of hepatic function to change with liver failure?
high bilirubin low urea high ammonia low glucose low albumin altered cholesterol
What are the 6 main things measured to test hepatic function?
bilirubin - check conjugated vs unconjugated
ammonia and urea glucose cholesterol - increase with cholestasis and decrease with hepatic failure bile acids (no gall bladder in horses) ammonium - hard to measure
How is icterus categorised?
pre-hepatic, hepatic and post hepatic
What is pre-hepatic icterus?
increased bilirubin production - haemolysis
mainly unconjugated bilirubin
What are the main causes of pre-hepatic icterus in horses?
neonatal isoerythrolysis, EIA, autoimmune haemolytic anaemia
What is hepatic icterus?
impaired hepatic uptake or conjugation of bilirubin
increased unconjugated than normal
Main causes of hepatic icterus in horses?
(hepatocellular disease,) anorexia
What is post-hepatic icterus?
impaired excretion of bilirubin
more conjugated
Main causes of post - hepatic icterus in horses?
cholangitis, cholangiohepatitis
Main ddx for horse icterus?
1) anorexia
2) anaemia
3) liver disease
Horse clinical signs of liver disease?
-common: depression anorexia colic (mild) weight loss icterus
-uncommon:
photosensitization, diarrhoea, bilateral laryngeal paralysis, haemorrhagic diathesis, ascites, dependent oedema