9.5.5: Chronic hepatobiliary disease Flashcards
Causes chronic hepatitis
- Idiopathic chronic hepatitis
- Copper-associated liver disease
- True copper storage disease
- Congenital vascular disease
- Neoplasia
- Biliary tract disease
What is the most common liver disease in dogs?
Idiopathic chronic hepatitis
Breed predisposition for idiopathic chronic hepatitis
- Cocker spaniels
- Labs
- Bedlington terrier
- Springers
- Standard Poodles
Breed predisposition for copper-associated storage disease
- Labds
- Dalmatians
- Skye terries
- Dobermanns
- WHWT
Breed predisposition for true copper storage disease
Bedlington terriers
Examples of primary hepatic neoplasia
- Hepatocellular carcinoma
- Haemangiosarcoma
- Biliary carcinoma
- Biliary adenoma
- Neuroendocrine tumours
- Leiomyosarcoma
- (Lymphoma)
Prevalence and presentation of secondary hepatic neoplasia
- Liver = very common site for metastases
- Can be clinically silent
- Can haemorrhage e.g. met from splenic haemangiosarcoma
Examples of biliary tract disease
- Biliary mucoceles
- Neutrophilic cholangitis
- Extrahepatic bile duct obstruction
- Bile duct rupture
Signalment of canine chronic hepatitis
- Breed predispositions: Cairn terriers, Dalmatians, Dobermanns, American and English Cocker Spaniels, English Springer Spaniels, Labs, Great Danes, Samoyeds
- Most common in middle-aged and older animals ~8 y.o.
- Seen younger in Springers and Dobermanns
Clinical signs of canine chronic hepatitis
- Waxing and waning clinical signs
- Inappetance
- Weight loss
- Vomiting ± haematemesis if GI ulceration
- Diarrhoea ± melaenia
- PUPD
- Lethargy/ depression -> true neuro signs / hepatic encephalopathy
Presentation and significant clinical exam findings of canine chronic hepatitis
May present as a case not responding to conventional treatment e.g. repeat V+/D+ that is not responding to diet; OR dog with variable appetite that is now showing weight loss/ abdo distension
Significant clinical exam findings
* Poor BCS
* Jaundice
* Ascites
What does chronic liver injury result in?
Activation of ito cells and extracellular matrix production
-> formation of fibrosis
-> portal hypertension and loss of hepatocyte function
How to definitively diagnose canine chronic hepatitis
Take biopsy
Will see:
* Variable mononuclear or mixed inflammatory infiltrate
* Hepatocellular apoptosis or necrosis
* Regeneration and fibrosis
Treatment options for chronic liver disease
- Ursodeoxycholic acid (UDA)
- Antioxidants: SAMe, silybin/ silymarin, Vitamin E
- Corticosteroids
- Antibiotics
- Diuretics
What is UDA and when is is useful? What must you remember when prescribing it?
- Useful in liver diseases where cholestasis is present or suspected
- Used under cascade in dogs and cats as no licensed options -> obtain owner consent for use
When are corticosteroids contraindicated in treatment of liver disease?
- If it is end-stage/ there is cirrhosis / there is bridging fibrosis
- If there is ascites / GI ulceration (= portal hypertension)
- In there is a risk of undiagnosed infection (bacterial, viral or fungal)
Potential adverse effects of corticosteroids used to treat liver disease
- Increased protein catabolism -> can cause or worsen hepatic encephalopathy
- Fluid retention can cause or worsen ascites
- Ulcerogenic effects -> can lead to GI ulceration (dexamethasone more so than prednisolone)
- Increased risk of infection/ could exacerbate existing infection
Use with caution!
Justification of antibiotic use in liver disease
- Management of hepatic encephalopathy - decreased ammonia formation by decreasing the bacterial load in the colon
- If histopathology changes suggest ascending cholangitis/ significant neutrophilic component to any inflammation
- Commonly appropriate choices: ampicillin, metronidazole; avoid fluoroquinolones unless culture and sensitivity
Management of ascites
- Furosemide - monitor potassium as this is not potassium sparing
- Spironolactone
- Peritoneal drainage - only if life threatening because ascites reforms rapidly, and this contributes to dehydration and worsens hypoalbuminaemia
Dietary management of chronic liver disease
- High quality, highly digestible and palatable protein sources - avoid white fish
- Complex carbohydrates preferred e.g. rice, pasta, potato
- Fat - only restrict if steatorrhiea develops
- Fibre - soluble and insoluble both good
- Commercial liver diets are protein and copper restricted - best reserved for dogs with copper accumulation or evidence of protein intolerance (e.g. hepatic encephalopathy, urate urolithiasis)
Prognosis and prognostic indicators for chronic liver disease
Prognosis very variable
* Might do well for years with supportive care
* Might have rapid deterioration despite good care
Negative prognostic indicators
* Ascites
* Jaundice
Ascites
Which type of PSS is shown here?
This is a normal liver
Which type of PSS is shown here?
Intrahepatic PSS
Which type of PSS is shown here?
Extrahepatic PSS
Clinical signs of PSS
- Neuro: lethargy, ataxia, obtundation, pacing, circling, blindness, seizures, coma
- GI: vomiting, diarrhoea, anorexia, pica, melaena, haematemesis
- Urinary: ammonium urate crystals -> haematuria, stranguria, pollakuria, urethral obstruction
Treatment of PSS
- Start by managing medically
- Surgical treatment offers greater survival; various techniques available
Clinical signs of hepatic neoplasia
- Often non-specific clinical signs: lethargy, poor appetite
- Signs may be associated with a complication e.g. abdo bleed if ruptured mass
- Palpable mass may be the only sign e.g. abdo distension, discomfort
- Signs often similar to chronic hepatitis
Diagnosis of hepatic neoplasia
- Lab findings may be similar to chronic hepatitis e.g. markers of hepatocellular damage, findings related to abdo bleed
- Diagnostic imaging: radiography, ultrasonography
- Definitive diagnosis: FNA for cytology, biopsy for histopath
Treatment for hepatic neoplasia
- Surgery = treatment of choice but assess for mets beforehand - take thoracic R, L lateral and DV rads with image taken on inflation (i.e. under GA) or consider CT
- Chemotherapy only effective for lymphoma
Signalment and cause of neutrophilic cholangitis
Signalment
* Uncommon in dogs. More common in cats
Cause
* Ascending infection/ haematogenous spread
* Organisms: Streps, E. coli, Klebsiella, Proteus spp.
Clinical signs associated with neutrophilic cholangitis
Variable
* Pyrexia
* Vomiting
* Jaundice
Clinical pathology associated with neutrophilic cholangitis
- Variable liver enzyme elevations, increased bilirubin
- Neutrophilia with/ without left shift
- (Bacterial infection hence neutrophilia ±left shift)
Diagnosis of neutrophilic cholangitis
- Bile centesis
- ± liver biopsy
Treatment for neutrophilic cholangitis
- Antibiotic treatment based on culture results
- Treat for 8 weeks minimum
Potential causes of extrahepatic bile duct obstruction
- Pancreatitis
- Pancreatic tumour
- Bile duct tumour
- Duodenal tumour / FB
- Gallbladder mucocoele
- Cholelithiasis
- Local trauma, inflammation
- Most common cause: secondary to acute or chronic hepatitis. Happens due to extrinsic compression of common bile duct into duodenum
Clinical signs of extrahepatic bile duct obstruction
- Signs relate to underlying reason for obstruction
- Very variable and non-specific in the early syages
- Depends on whether partial or complete obstruction
- May start with mild abdominal pain
Diagnosis of extrahepatic bile duct obstruction
- Clin path: ALP, bilirubin usually v high. Other abnormalities associated with underlying cause.
- Ultrasound: determine if cause can be seen e.g. pancreatitis, cholelith
Causes of bile duct rupture
Usually the same as extrahepatic bile duct obstruction (EHBDO):
* Pancreatitis
* Pancreatic tumour
* Bile duct tumour
* Duodenal tumour/ FB
* Gallbladder mucocoele
* Cholelithiasis
* Local trauma, inflammation
* Acute / chronic hepatitis
Management of extrahepatic bile duct obstruction
- Medical management for pancreatitis
- Other causes often require surgical mangement
Consequences and clinical signs of bile duct rupture
- Bile peritonitis -> abdominal effusion (may be infected if secondary to ascending cholangitis; important to culture abdo fluid in these cases)
- Profound jaundice is common
Treatment of bile duct rupture
- Manage underlying cause
- Cholecystectomy: histopath and culture of gallbladder wall for followup treatment decisions
Indications for cholecystectomy
- Ruptured gallbladder
- Primary neoplasia of the gallbladder - very rare
- Cholecystitis that is unresponsive to medical management
- Gallbladder mucocoele
- Cholelithiasis
Diagnosis of cholelithiasis
Ultrasound
Gallbladder mucocoele
distension of the gallbladder by inappropriate amounts of mucus (mucocoele).
* Quite uncommon
* Diagnosed on ultrasound
* Possibly associaed with endocrine diseases e.g. hypoT4, hyperadrenocorticism, hyperlipidaemia
What should you do before a liver biopsy?
Run a clotting profile (assess coagulation factors to make sure your patient is stable enough to have the biopsy done)
What is the most specific marker of hepatocellular injury in the dog?
ALT
