Jaundice/Liver Disease Flashcards
Define pre-hepatic jaundice
increased haem production in XS of liver’s ability to take up and process
Define hepatic jaundice
disturbed handling of bilirubin by the hepatocytes
potential causes of post-hepatic jaundice
- sepsis or severe inflm disease (mild but can see jaundice)
- hyperT in cats - mild inc. bili but not overt jaundice
- fever + starvation = mild inc. bili but not overt jaundice
DDx pre-hepatic jaundice
- Haemolysis
- IMHA: primary and secondary
- Infections eg. Mycoplasma haemofelis
- drugs/toxins eg. zinc, copper, lead, onions
- congenital haemolytic anaemias
name an infectious cause of haemolysis
mycoplasma haemofelis
ddx (4) for primary hepatic jaundice in dogs
D A M N: hepatobiliary neoplasia I: chronic hepatitis, leptospirosis T: toxin/drug induced V
ddx (7) for primary hepatic jaundice in cats
D A M: hepatic lipidosis + amyloidosis N: hepatobiliary neoplasia (lymphoma) I: cholangitis/cholangiohepatitis (+/- post hepatic), FIP, lymphocytic cholangitis T: toxic/drug induced V
2 major causes of post-hepatic jaundice
- intrahepatic biliary compression
- extrahepatic obstruction (dz of gall bladder, bile duct, duodenum or pancreas
4 ddx of extra-hepatic obstruction
- pancreatitis
- neoplasia: bile duct, pancreas, duodenum
- bild duct occlusion: cholelithiasis, sludged bile
- bile duct or gall bladder rupture
2 characteristics of prehepatic jaundice on bloods
- sig. + regenerative (or pre-) anaemia
2. mild to mod liver enzyme increases
how can hepatic/biliary tract US be useful in differentiating causes of jaundice?
reveals bile duct obstruction and dilatation, may show abnormal parenchyma
3 causes of chronic liver disease
- canine chronic hepatitis (+ copper-assoc. hepatitis)
- feline cholangitis/cholangiohepatitis
- hepatobiliary neoplasia
CS of acute liver injury/failure
anorexia, vom, neuro signs, PU/PD
w/ varying degrees of icterus, coagulopathy, hepatic encephalopathy
list 5 toxic causes of acute liver failure
- aflatoxins
- amanita mushrooms
- blue-green algae
- cycad palms
- xylitol
list 4 drugs assoc. w/ acute liver failure
- oral benzos in cats
- carprofen
- sulfonamides
- phenobarbitol
list 6 infectious causes of acute liver disease
- infectious canine hepatitis
- FIP
- lepto
- Platynosum fastosum
- Salmonella
- Toxoplasmosis
Diagnosis of acute liver failure
- Biochemical evidence of reduced liver function + increased PT and/or PTT (>1.5x)
- Liver US
6 branches of acute liver disease management
- stop any existing meds
- IVFT + lytes (usu. low in potassium)
- Plasma transfusion (clotting factors)
- Treat hepatic encephalopathy
- Antimicrobials: amoxicillin 20mg/kg q8h IV
- Vit.K 1mg/kg q24h SC
explain the aetiology of hepatic lipidosis in cats
- Acute - partial or complete anorexia 1-2wks –> a neg. energy balance
- assoc. w/ poor appetite (stressful event/other disease)
- Reversed by nutrition and correction of underlying disease
US appearance of hepatic lipidosis
- hepatomegaly characterised by hyperechoic appearance of liver by US
6 branches of treatment of hepatic lipidosis in cats
- IVFT + lytes
- Feeding tube: N-tube initially (2-3d), then GA and place O/G- tube for proactive nutrition
- Correct underlying disorder (that caused the anorexia)
- Maropitant 1mg/kg
- Tx hepatic encephalopathy if present
- +/- L-carnitine 250mg/cat q24h PO
Later signs of chronic hepatopathies
- prolonged recovery from sedation/GA
- icterus
- ascites
- hepatic encephalopathy
- bleeding tendencies (bruising, melena)
what test should you perform prior to liver biopsy?
coag - PT and APTT often prolonged by liver disease
how many g of liver issue are needed for diagnostics?
4g - culture, copper assessment, histopath
ALT is elevated in liver disease but also elevated w/ …..
…many rel. benign disorders - anaemia, hypoxaemia, trauma
ALP activity is elevated in liver disease but also induced by:
- corticosteroids (iatrogenic, cushing’s, phenobarbitol)
- young animals (<6m)
- infection/sepsis
- Even mild bile duct dx (IBD, pancreatitis)
- Bone disease
average age of dog w/ chronic hepatitis
6-8ys (range 2-14ys)
5 arms of tx of chronic hepatopathies in dogs
- reduce inflam: immunosuppressant, anti-ox, reduce cholestasis
- inhibit/reduce fibrosis
- reduce Cu accumulation by enhancing its excretion
- Manage the complications - reduce ascites, control and reduce gastric bleeding, and prevent and control hepatic encephalopathy
- Monitor progress - rpt bloods +/- biopsy
what is UDCA?
ursodeoxycholic acid - a natural hydrophilic bile acid which improve flow of bile and is an antioxidant which reduces inflammation
when is UDCA contraindicated?
in bile duct obstructions
UDCA dose
10-15mg/kg q24h PO
when can you use prednisolone in chronic hepatopathies?
- rule out infectious causes
- 1mg/kg q24h PO taper over time
give 4 anti-ox. compounds used for chronic hepatopathies
- S-adenosyl-L-methionine
- Silymarin
- Vit E
- Vit C
SAMe dose
20mg/kg q24h PO
milk thistle dose
50-200mg/dog q24h PO
3 dietary changes to manage a dog w/ chronic hepatopathy
- mod restricted protein
- reduce copper
- increase anti-ox (Vit.E/C, selenium)
why restrict protein in chronic hepatopathies?
- reduces ammonia formation —> hepatic encephalopathy
what are the 3 clinically recognised forms of feline inflammatory liver disease?
- neutrophilic cholangitis (NC)
- Lymphocytic cholangitis (LC)
- Chronic cholangitis (caused by liver fluke)
what causes neutrophilic cholangitis?
ascending bacterial infection of biliary tract from intestine
CS of neutrophilic cholangitis
cats are yellow and unwell
Tx of neutrophilic cholangitis in cats
- Antibiotics: aminopen + pradofloxacin 4-8wks
- UDCA 10-15mg/kg q24h PO
- Opioids
- Supportive care
Tx of lymphocytic cholangitis in cats
- Prednisolone 2mg/kg q24h PO
- UDCA 10-15mg/kg q24h PO
- Supportive care
HE is caused by?
failure to detoxify ammonia from the GIT by the liver in the urea cycle
HE causes signs assoc. w/ which anatomical part of the brain?
symmetrical forebrain signs
2 causes of a young animal with HE
- Congenital PSS
2. Congenital hepatic fibrosis –> acquired shunts + ascites
2 causes of adults w/ HE
- Portal hypertension assoc. w/ liver disease and acquired shunts
- Acute loss of liver function (acute hepatitis)
3 forebrain signs assoc. w/ HE
- Altered mentation: obtundation, aimless pacing, stargazing, head pressing
- Seizures (less common)
- Central blindness
list 5 exacerbating factors of HE
- Protein in the GIT
- Hypokalaemia
- Alkolosis
- Dehydration
- Sepsis/infection
immediate management plan for HE
- tx dehydration
- tx GIT ulceration
- Manage coagulopathies
- Empty the GIT
- Avoid drugs that reg. hepatic metabolism
technique for emptying the GIT in acute management of HE
- Colonic lavage (under propofol/iso GA if needed) –> warm water enemas followed by retention enemas until signs stop (lactulose and water mixture 3:7 q6h per rectum).
what drugs do you avoid w/ HE?
those which require hepatic metabolism eg. diazepam and barbiturates
ongoing management of HE
- Lactulose
- Antimicrobials
- Dietary protein restriction
what is the MOA of lactulose in management of HE
Lactulose lowers colonic pH + increased GIT transit time reduces bacterial loads
admin/dose of lactulose
titrate to effect - soft stool consistency
2-5ml q12-24h in small dogs
10-20ml q12-24h in large dogs
name an antimicrobial used to decrease bacterial load (and toxins) in HE management
amoxicillin
