Hepatic Dr Yvorchuck Flashcards
What is the triad of CS for Cholelithiasis in the horse
Colic
Pyrexia
Icterus
What is the triad of CS for Pyrrolizidine Alkaloid toxicity in equines
Fibrosis
Bile duct proliferation
megalocytosis
what are bw changes seen in hepatic dysfunction in horses
on CBC:
- RBCs = mostly ACD*
- WBC = varies but expected to be elevated as almost alway some infectious component*
in acute dz = leukopenia likely
Fibrinogen = varies depending on timeline & severity
likely hyperfibrinogenemic (chronic)
on Chemistry:
- Glu = possibly hypoglycemic, often hyperglycemic*
- BUN = <10 considered significant for liver dysfunct.*
- Protein = rarely hypoalbuminemic or hypoproteinemic, may see hyperglobinemia d/t chron. inflammatory dz*
- Bilirubin = serum bile aciids (SBA) increased esp chronic/severs dz*
Liver enzymes = SDH, ALP, AST, GGT gives clues as to specific dz process
hepatocellular = SDH -> ACUTE, AST -> Chronic
biliary = ALP -> ACUTE, GGT -> Chronic
what is the most useful indicators of liver injury
SDH, GGT & SBA
in the face of significant liver dz at least 1 of the 3 are elevated
SDH = acute liver
SBA = end stage liver
what does GGT mean
ductal enzyme denoting biliary dysfunction
also involved in repair phase, not only cell dysfunct. & renal
what does GGT elevations in urine indicate
that the GGT is of renal origin not liver (too big to pass through glomerulus)
other than liver dysfunction what other reason might you see an incr in ALP in an equine
ALP is also a bone enzyme so it might be elevated in Young Growing horses!
Remember context when interp. BW!
When interpreting SDH what is good to remember
That SDH returns to baseline in 3-5 days so can indicate point insult & if shows up again = new insult
will horses likely have just hepatocellular or biliary dysfunction
No!
Very rare that will have one or the other exclusively - more likely to have both dz processes concurrently to some degree
What should you suspect when you see a triad of CS referable to coagulation, nervous & cutaneous systems
Liver dysfunction
involvement of these 3 systems in a horse think LIVER!
usually not a single horse problem - more likely a “herd” issue think toxins
what are 4 clincal presentations (problems) that can indicate liver dysfunction
- Icterus
- Hepatic encephalopathy
- Photosenstization
- Clotting disorders
- w or w/o Colic
Icterus
conjugated bilirubin causes more pronounce icterus than unconjugated
the pattern of bilirubin elevation helps differentiate b/t
Pre & post-hepatic hyperbilirubinemia
how are total bilirubins measure
unconjugated (indirect) = calculated
conjugated (direct) = measured
what is elevated direct bilirubin a highly specific indicator or
liver failure
if direct >/= 25% of total -> predominantly biliary disease
how commonly is hepatic encephalopathy seen in liver dysfunction
80% of case
d/t accumulation of blood ammonia
must differentiate from idiopathic hyperammonemia:
rare complication of severe GI dz
Absence of markers of hepatic dz.
