hepatobiliary 2: acute hepatitis Flashcards
infectious causes of acute hepatits?
Canine adenovirus-1
Leptospirosis
Clostridium spp.
Ehrlichia canis
toxins that can cause acute hepatitis
- Mycotoxins, aflatoxicosis
- Blue green algae (cyanobacteria)
- Amanita mushrooms
- Xylitol
- Organic solvents
- Cycad / sago palms
deugs that can cause acute hepapitis
Carprofen
Acetaminophen (cats»_space; dogs)
TMS
Azathioprine
Diazepam (oral – cats)
Ketoconazole
Methimazole (cats)
Antiepileptics (phenoparbital, zonisamide)
Acute Hepatic Injury: Presentation
Clinical signs related to hepatic cell necrosis & inflammation
* Non-specific: anorexia, vomiting, PU/PD
* More specific: abdominal pain, ascites
* Liver-specific: icterus
- Signs of coagulopathy, hepatic encephalopathy can be present
Acute Hepatic Injury: Diagnosis - biochem and lab findings
Biochemical profile:
* Marked elevations ALT, AST occur early in the process
* Signs of cholestasis often present
* Possibly azotemia (pre-renal, or renal from shared etiology)
Otherlaboratoryfindings
* Anemia (blood loss, other causes)
* Coagulopathy
* Signs of DIC
Leptospirosis testing methods
- Point-of-care antibody tests ( Zoetis Witness)
- PCR
- Microscopic agglutination test (MAT)
Point-of-care antibody tests ( Zoetis Witness) for lepto; what may occur in acute disease?
- IgM Can be negative in acute disease
PCR lepto test; what do we sample? when? cuation with antibiotics?
- Performed on blood and urine
- Typically positive in blood in first 10 days of infection, urine thereafter
- Antibiotics cause negative result
lepto Microscopic agglutination test (MAT); how does it work/ what is detected? how does vaccination affect this?
- Antibodies to several serovars
- 4-fold increase in acute and convalescent (2-weeks later) supportive of diagnosis
- Vaccination can cause positive titres
Serovars covered in North American leptospirosis vaccination
- ‘CPIG’
- Canicola, Pomona, Icterohaemorrgiae, Grippotyphosa
Acute Hepatic Injury: Diagnosis - what do we see with imaging?
Abdominal imaging
* Liver can be large, presence of ascites
* Hepatic parenchyma diffusely altered echogenicity
* Ultrasound can be normal
- Ultrasound findings not specific, do not define extent of injury
Acute Hepatic Injury: Treatment
Treatment of underlying cause, if known
* Toxin: gastric decontamination
* Empirical treatment Leptospirosis if risk in your area (doxu
Liver supportive treatment
* Antioxidant (SAMe and others, N-acetylcysteine as an IV option)
* Ursodiol if cholestatic
Intensive care support
* GIulceration, coagulopathy
why is the liver prone to oxidative damage?
- Central role in metabolism of drugs, toxins
- Large population of macrophages (Kuppfer cells)
purpose of glutatione? when may it be reduced?
- Essential anti-oxidant in hepatocytes
- Reduced levels found in bile duct obstruction, lipidosis, inflammatory liver disease
is oxidative injury often important in canine /. feline hepatobiliary disease?
- Oxidative injury likely important in canine & feline hepatobiliary disease
Commonly used anti-oxidants for liver
- SAMe
- Silymarin (Milk thistle)
- Vitamin E
- N-Acetylcysteine
SAMe & silymarin available together in some commercial products
reccomended antioxidant for liver support, and why
Recommend to use veterinary grade SAMe products
* Over the counter products might not contain appropriate amounts despite label
Evidence-based indications for antioxidants for liver support, for amanita, Acetaminophen toxicity, aflatoxins, Lomustine
- Amanita toxicity – silymarin improved outcomes
- Acetaminophen toxicity, aflatoxins – N-acetylcysteine improved outcomes
- Lomustine – SAMe/silymarin protective
Suggested indications for anti-oxidants for liver
- Acute liver injury
- Canine chronic hepatitis
- Feline hepatic lipidosis
can or should we combine antioxidants for liver treatments?
- Ideal agent / combination of agents unknown
> Generally safe
Choleretics; what do they do?
- Modulates bile acid pool (less toxic to hepatocytes)
- Anti-inflammatory and anti-oxidant properties
- Only absolute contraindication for choleretics? when are they often used?
Only absolute contraindication is complete biliary obstruction
* Often added to patients with cholestasis as part of their condition * Limited evidence
choleretic which is given for liver support
Ursodeoxycholic acid (ursodiol)
* Synthetic hydrophilic bile acid
what animal is hepatic nodular hyperplasia common in? how many nodules?
- Hepatic nodular hyperplasia very common in older dogs
- Single o rmultiple nodules
nodular hyperplasia presentation; enzymes, signs
Presentation
* Mild to moderate elevations in liver enzymes, typically found incidentally
* No clinical signs
Nodular Hyperplasia; can we see it on ultrasound? what type of liver change is this?
Can appear on ultrasound as a neoplastic process but is a benign, regenerative change
CASE:
* Problem list:
* Pyrexia
* Icterus
* Recent decrease appetite, now anorexia
* Decreased MCS and BCS
* Dehydrated
* Chronic vomiting
> what are our initial plans?
- Biochemical profile
- Complete blood count
- Urinalysis
- FeLV/FIV
Cholangitis - what is this? where can it extand? what animal is this common in?
Inflammation of the biliary tract
* Can extend into hepatic parenchyma (“cholangiohepatitis”)
- Cholangitis affects cats»_space; dogs
Feline Cholangitis - what liver values do we expect to be high?
- Serum ALP, GGT
- Serum bilirubin
- (ALT, AST elevation if cholangitis extends into hepatic parenchyma)
> BUT remeber cats have such short enzyme half lives that we may not see these elevated values
why may serum ALP and GGT be elevated? how do these enzymes differ in cats vs dogs?
- Biliary epithelium react to inflammation, other stimuli
- Increased in intrahepatic or extrahepatic cholestasis, drug effect (dogs)
- Shorter half-life in cats vs dogs
what can cause a rise in serum bilirubin levels? what will PCV look like? what mix will we see in most hepatobiliary disease?
- Pre-, hepatic, and post-hepatic causes
- Normal PCV = intra- or extra-hepatic cholestasis present
- A mix of conjugated and unconjugated bilirubin in most hepatobiliary diseases
diseases that are commonly concurrent with feline cholangitis? why?
- Concurrent pancreatitis and/or intestinal disease common
> “Triaditis”
Shared pathophysiology:
* Anatomy: pancreatic & bile duct proximity; sphincter of Oddi spasm in IBD
* Common triggers / causative agent
* Likelymultifactorial
Neutrophilic (Suppurative) Cholangitis - what is the likely cause of this? is it usually acute or chronic?
- Likely ascending bacterial infection from intestine
> E.coli, Streptococcus, Klebsiella, Pseudomonas, Enterococcus, Clostridium, etc
> Neutrophilic inflammation of bile lumen, ducts, edema - Typically acute in nature
> A more chronic, mixed inflammatory stage also recognized
Neutrophilic Cholangitis: Presentation - what signalment? clinical signs?
- Any signalment of cat, but typically young to middle-age
- Clinical signs usually <1 month
> Pyrexia, lethargy, icterus, other non-specific signs
> Signs of pancreatitis or intestinal disease can be present and overlap
Neutrophilic Cholangitis: Diagnosis - labwork and ultrasound results?
- Labwork and imaging results not sensitive or specific
- Often:
> Neutrophilic inflammation on CBC
> Elevated bilirubin, ALT (sometimes ALP)
> Labwork can be normal - Ultrasound:
> Enlarged liver, dilated biliary tracts, gall
bladder debris might be present
> +/- Pancreatitis, intestinal disease
Neutrophilic Cholangitis: how do we get a difinitive diagnosis? risks and contraindications?
- do we have some other options that might be helpful, aside from imaging, labwork?
Definitive diagnosis requires cholecystocentesis & bile culture
* Risks (overall low): GB rupture, hemorrhage
* Contraindicated if noted GB wall devitalization
- Liver fine needle aspirate
> Neutrophilic inflammation, non-specific - Hepatic biopsy
> Portal and biliary duct neutrophilic inflammation
Neutrophilic Cholangitis - can we always get a diagnosis? how do we often proceed?
can be difficult to get difinitive diagnosis
* Often: empirical treatment after presumptive diagnosis
when is sampling for neutrophilic cholangitic contraindicated?
- Sampling contraindicated if uncontrolled coagulopathy
Neutrophilic Cholangitis: Treatment
- Antibiotics for 4-6 weeks: ideally based on culture and sensitivity
- Empirical choices targeting gram positive & negative, aerobe and anaerobe (E coli most
common); bile secretion; bactericidal
> Fluoroquinolone (+/- potentiated penicillin/ clindamycin)
> Penicillin + metronidazole
> No enrofloxacin in cats! (Prado, marbofloxacin appropriate) - IV antibiotics if signs of sepsis or systemic illness
- Hospitalization for IV fluids, nutritional support usually required
- Anti-emetics, appetite stimulants
- Vitamin K if coagulopathy (plasma in severe cases)
- Consider:
> S-adenosylmethionine, silybin, and
ursodeoxycholic acid (ursodiol) - Treatment for concurrent disease (e.g., pancreatitis)
> Analgesia with opioids
> If signs of intestinal disease, eventually consider diet suitable for IBD
Neutrophilic Cholangitis - what should we consider doing prior to discontinuing antibiotic treatment? what other disease might we want to investigate?
- Consider rechecking hepatic values prior to discontinuing antibiotics
- Patients might require further investigation for other diseases
> IBD, chronic pancreatitis
Neutrophilic Cholangitis: Prognosis
- Most cats recover with treatment, recurrence not common
- Concurrent disease a factor in prognosis
- Complications rare
> GB obstruction with cholelith, abscessaction
