Lecture 13 2/11/25 Flashcards
What are the characteristics of canine chronic hepatitis?
-inflammatory reaction in the liv3er continuing without improvement for 6+ months
-confirmed via histology
-most common primary liver dz in dogs
-often idiopathic
-higher prevalence of chronic bacterial infections in dogs with CCH
What are possible etiologies for CCH?
-infection
-medications
-toxins
-drug-induced chronic hepatitis
-excess hepatic copper accumulation
-autoimmune chronic hepatitis
What is the most common cause of toxin-induced CCH?
copper accumulation
What is the pathophysiology of CCH?
-hepatic injury results from hepatocellular death and release of inflammatory mediators
-inflammatory cell infiltration and immune system response contributes to ongoing injury
-ongoing injury eventually leads to necrosis and fibrosis
What is the signalment of CCH?
-seen in middle-aged to older dogs
-can be any breed, but some are predisposed
Why do signs of CCH not show up until late in the disease process?
the liver has a large reserve capacity and can continue functioning normally early in disease
Why is it important to test dogs with persistent increases of liver enzymes early?
waiting for clinical signs means the patient will lose a lot of functional liver capacity; early diagnosis can lead to earlier treatment and preservation of function
What are the less specific clinical signs seen in CCH patients?
-fever
-lethargy
-weakness
-hyporexia/anorexia
-weight loss
-abdominal pain
-vomiting diarrhea
What are the more specific clinical signs seen in CCH patients?
-PU/PD
-icterus
-ascites
-hepatic encephalopathy
What are the characteristics of liver enzyme clin path in CCH?
-liver enzymes are increased in a mixed hepatocellular and cholestatic pattern
-initial increase in leakage enzymes; ALT and AST
-cholestatic enzymes increase later
-enzymes can wax and wane over the course of months
What causes abnormal markers of hepatic synthetic function in CCH?
-hepatocyte loss
-fibrosis limiting normal sinusoidal blood flow
What are the characteristics of ultrasound as a diagnostic tool for CCH?
-not sensitive or specific for the diagnosis of CCH
-may see. small, hyperechoic liver
-helpful to identify neoplastic masses, ascites, and APSS
What are the characteristics of hepatic cytology as a diagnostic tool for CCH?
-inadequate for diagnosis of CCH
-can help to rule out diffuse neoplastic infiltration and suppurative inflammation
What tests need to be done to diagnose CCH?
-histology
-aerobic/anaerobic culture
-copper quantification
What are the histologic features of CCH?
-inflammation in any region of the liver
-hepatocellular death
-variable grades of fibrosis
What are the main management steps for CCH?
-discontinue hepatotoxic drugs
-treat underlying disease; may be enough to stop progression
-antioxidant therapy to control necroinflammatory/cholestatic processes until liver enzymes normalize
What are further recommendations for treatment of CCH?
-antiemetics and gastroprotectants
-antibiotics if bact. infection is suspected
-treatment for fibrosis if present on histology
-protein restriction ONLY if patient develops acquired stunts or hepatic encephalopathy
What are the specific management steps for copper-associated chronic hepatitis?
-lifelong dietary restriction; commercial liver diet + low-copper protein source supplementation
-chelation of copper if concentrations reach 750 ug/g of centrilobular accumulation or 1500 ug/g overall accumulation
What are the characteristics of D-penicillamine?
-bind hepatic copper for elimination in urine
-upregulate metallothionein in enterocytes for fecal elimination of dietary copper
-has anti-inflammatory and anti-fibrotic properties
How long should D-pen be used?
-6 to 9 months until copper concentrations normalize when combined with a copper-restricted diet
-longer if not given with a copper-restricted diet
How is the efficacy of copper hepatitis determined?
-repeat biopsy and quantification is best
-normalization of serum ALT is a good surrogate
Which treatments can be used for maintenance of copper hepatitis?
-D-pen given at a reduced frequency
-administration of zinc to block enteric copper absorption
-D-pen and zinc CANNOT be given concurrently
What are the options for immune modulation in nonsuppurative immune-mediated CCH?
-prednisone/prednisolone
-dexamethasone if ascites occurs
-steroids combined with secondary immunosuppressive med.
-cyclosporine alone
**often lifelong therapy
What is the prognosis of CCH?
-depends on etiology and histologic grade
-infectious and copper-associated hepatopathy have good prognosis
-fibrosis could be reversible; therapy indicated even in severe fibrosis
-ascites and icterus are negative prognostic indicators in dogs with idiopathic CCH
What is canine vacuolar hepatopathy?
excessive accumulation of cytosolic glycogen, fat, and water within hepatocytes
What is the predominant etiology for canine vacuolar hepatopathy?
secondary to disease in other organs
What are the characteristics of glycogen-like vacuolar hepatopathy of scottish terriers?
correlated to abnormal androgenic hormone production
What are the characteristics of canine familial hyperlipidemia?
-occurs in miniature schnauzers
-canine primary hepatic steatosis (excessive fat in liver)
-caused by delayed clearance of dietary triglycerides
-causes increases in fasting triglycerides and/or cholesterol
What is the pathophysiology of vacuolar hepatopathies?
-dysregulation in the synthesis, storage, and catabolism of glycogen leads to hepatocellular swelling and dysfunction
-failure to address underlying dz allows hepatocellular swelling to affect normal intracellular processes
-hepatocellular swelling also affects extracellular canalicular bile flow
-continued cellular degeneration leads to stromal collapse and distortion of sinusoidal blood flow
What is the clinical presentation of vacuolar hepatopathies?
-middle-aged to older dogs
-any breed or gender
-hepatomegaly on physical exam
-moderate to severe increase in ALP and ALT
-progressive increase in leakage enzymes with ongoing hepatocellular damage
What are the differential diagnoses for vacuolar hepatopathies?
-primary or secondary cholestatic liver dz
-neoplasia
What are indicators for preliminary diagnosis of vacuolar hepatopathy?
-moderate to severe ALP increase
-hepatomegaly
-hyperechoic parenchyma with hypoechoic nodules
-decreased density of hepatocytes on cytology
Why is histology needed in vacuolar hepatopathy diagnosis?
to diagnose concurrent necroinflammatory dz
What are the management steps for vacuolar hepatopathy?
-therapy of underlying condition
-discontinuation of glucocorticoids, steroidogenic drugs, and herbal remedies
-antioxidant therapy
-low fat diet for hyperlipidemia
–omega-3 fatty acids if low fat diet fails
What is the prognosis for vacuolar hepatopathy?
-good if underlying etiology is identified and treated
-can see a progressive degenerative process correlated w/ development of hepatocellular carcinoma
What are the characteristics of gallbladder mucocele?
-abnormal accumulation of mucin and inspissated bile within gallbladder lumen
-specific etiology unknown
Which co-morbidities are associated with gallbladder mucocele?
-dyslipidemia
-endocrinopathy
-gallbladder hypomotility
-cholelithiasis
What is the pathophysiology of gallbladder mucocele?
-excessive secretion of abnormal gel-forming mucin from gallbladder epithelium leads to gallbladder distension and mural ischemia/necrosis
-obstruction of the cystic and common bile ducts occurs secondary to extension or migration of mucin
What is the clinical presentation of gallbladder mucocele?
-older, small to mid-sized dogs
-may be asymptomatic
-GI signs, cranial abdominal pain, and icterus
-predominating increase in cholestatic enzymes (ALP, GGT)
-increase in leakage enzymes (ALT, AST
-variable changes in WBC, bilirubin, and cholesterol
What are the differential diagnoses for gallbladder mucocele?
-cholecystitis
-hemocholecyst
-accumulation of gravity-independent gallbladder sludge due to outflow obstruction
How is gallbladder mucocele diagnosed?
abdominal ultrasound
When is cholecystectomy indicated?
-ruptured gallbladder mucoceles
-symptomatic patients
-those with moderate/severe biochemical changes
What are the characteristics of cholecystectomty?
-bacterial cholecystitis is a common co-morbidity
-broad-spectrum ABs should be given to decrease complications from septic peritonitis
-vitamin K1 given peri-operatively
-choleretics should not be given if GB wall is compromised or if bile duct is obstructed
What are the medical management steps for gallbladder mucoceles in asymptomatic/minimally affected patients?
-ursodeoxycholic acid
-therapy of underlying dyslipidemias/endocrinopathies
-serial rechecks; cholecystectomy if no improvement
What is the prognosis for gallbladder mucoceles?
-post-op survival is relatively high
-survival is better in patients undergoing elective surgery
-hyperbilirubinemia is a poor prognostic indicator
