Exam 3 - Feline Liver Disease Flashcards
what are the 5 most common hepatic diseases in cats?
- hepatic lipidosis - > 50% of feline hepatic disease
- feline cholangitis syndrome - 25% of feline hepatic disease
- lymphosarcoma
- feline infectious peritonitis
- reaction to a drug or toxin
how do you differentiate hepatocellular disease from biliary tract obstruction in a cat?
abdominal ultrasound
what is the classic history of a cat with hepatic lipidosis?
obese cat that stops eating & then becomes icteric
what is the pathophysiology of hepatic lipidosis in cats?
cat stops eating - starvation causes lipidosis by causing body fat to be mobilized
too much fat is mobilized, so there is more fat entering the hepatocytes than there is exiting & at the same time the fat is being broken down, less protein is being taken into the body due to anorexia
fat can’t get out of the liver because there is no protein to form lipoproteins
why are obese cats more at risk for hepatic lipidosis?
these cats can mobilize large amounts of fat very quickly
why is hepatic lipidosis a positive feedback loop?
cat can get sick from any cause & become anorexic
cat breaks down fat while simultaneously becoming deficient in protein
fat builds up in the liver & hepatic cytoplasm is replaced with fat
hepatic insufficiency develops & this hepatic disease causes anorexia
what are the classic clin path findings seen in hepatic lipidosis cats?
hyperbilirubinemia, increased ALP despite normal ALT
what further diagnostics are needed for a cat with a high ALP, hyperbilirubinemia, normal ALT, & normal GGT? why?
liver biopsy
FNA can easily miss other infiltrative hepatic diseases that could cause lipidosis - if an FNA only detects mild to modest amounts of fat in hepatocytes of a seriously ill cat/cat fails to respond to treatment
consider a more substantial liver biopsy
what treatment is absolutely necessary for a cat with hepatic lipidosis?
feeding tube!!!!! high protein/high energy dense diet & monitor for refeeding syndrome
appetite stimulants - can help prevent lipidosis but are poorly effective in patients with established clinical lipidosis
IV fluids - may have to supplement potassium & phosphorus
vitamin K
SAMe, vitamin E
what is the prognosis of hepatic lipidosis in cats?
20-30% mortality depending upon how sick the animal is upon admission
what are the two types of feline cholangitis syndrome?
due to ascending infection - neutrophilic cholangitis
immune-mediated disease - lymphocytic cholangitis
what are the classic clin path findings seen in feline cholangitis syndrome?
increased ALT, ALP, & bilirubin
finding a major increase in ALT is classic for cholangitis but isn’t reliable for distinguishing cholangitis from lipidosis however increased GGT is more common in cholangitis
how do you make a definitive diagnosis for feline cholangitis syndrome?
usually need a hepatic biopsy & culture/cytology on bile
what supportive therapy is used for treating both types of feline cholangitis syndrome patients?
ursodeoxycholic acid, vitamin E, & SAMe
what treatment is indicated for neutrophilic cholangitis in cats?
ANTIBIOTICS!!!! amoxicillin, ampicillin, cefazolin, cefadroxil, or enrofloxacin
need to use something that kills both aerobes & anaerobes
what treatment is indicated for lymphocytic cholangitis in cats?
prednisolone at 1-2 mg/kg/day, ursodeoxycholic acid, & SAMe - don’t send home too many meds
chlorambucil may be useful in cats that don’t respond to pred
NO AZATHIOPRINE!!!
what drugs are known to be hepatotoxic to cats?
azathioprine
oral diazepam
aspirin
voriconazole
acetaminophen
what causes FIP?
mutated feline coronavirus
what clinical signs are seen in cats with FIP?
fever, CNS signs, ocular lesions
how is FIP diagnosed?
history, physical exam, hyperglobulinemia, thrombocytopenia, may see ALT/ALP, & may see jaundice
T/F: cats with FIP always have effusions
false
what disease is a major cause of CNS signs in cats under 5-8 years of age?
feline infectious peritonitis
_________ lesions, especially uveitis, can be suggestive of FIP
ocular
T/F: FeLV status is not useful in diagnosing or eliminating lymphoma in cats
true
what lab abnormalities may be seen in a cat with hepatic lymphoma?
normal or increased ALT and/or ALP
what are some pre-hepatic causes of icterus in cats?
causing hemolysis
secondary IMHA - mycoplasma, FeLV, cytauxzoon, lymphoma
primary IMHA - uncommon
non-immune mediated - heinz bodies, hypophosphatemia
what pathology is seen on this blood smear?
heinz bodies
what are some hepatic causes of icterus in cats?
cholangitis
hepatic lipidosis
neoplasia - lymphoma, biliary carcinoma, biliary cystadenoma
FIP
toxins - acetaminophen, diazepam, phenols, & tetracycline
what are 6 examples of post-hepatic causes of icterus in cats?
- cholecystitis
- pancreatitis
- biliary carcinoma/cystadenoma
- liver flukes
- biliary rupture
- cholelithiasis
what are the 4 most common causes of icterus in cats?
- feline hepatic lipidosis
- cholangitis
- hemolytic anemia
- feline infectious peritonitis
what is the first question you should consider when presented with an icteric cat?
is the cat anemic or not!
is there a steroid induced ALP in the cat?
no
are minor increases in ALP/ALT in cats clinically significant?
YES!!!
the magnitude of liver enzyme increases in cats is less than dogs & extrahepatic disease can cause secondary increases in ALT/ALP activity
what 4 body organs/systems are you checking for abnormalities in an abdominal ultrasound in an icteric cat?
- hepatobiliary
- pancreatic
- gastric
- intestinal
what happens when there is triglyceride accumulation in the liver of cats?
intrahepatic cholestasis
icterus
vitamin K deficiency
what are the risk factors for hepatic lipidosis?
obese cats
periods of anorexia - protein/calorie malnutrition
underlying disease
what is the most common underlying disease in cats with hepatic lipidosis?
IBD
what is the typical signalment of cats with hepatic lipidosis?
middle aged cats
no breed or sex predilection
what is the minimum age of cats with hepatic lipidosis? median? max?
minimum - 6 months
median - 7 years old
max - 20 years old
what signs are seen on physical exam of cats with hepatic lipidosis?
icterus - 70% of cats
overweight/obese cats
weakness - cervical ventroflexion & plantigrade stance
ptyalism
rare - signs of hepatic encephalopathy
vomiting/diarrhea
what may be seen on urinalysis of a cat with hepatic lpidosis?
bilirubinuria
lipiduria
what is seen on hematology of a cat with hepatic lipidosis?
non-regenerative anemia - heinz bodies & poikilocytosis
mild lymphopenia & neutrophilia
inflammatory leukogram suggests that there is an underlying inflammatory disorder
what is seen on abdominal ultrasound of a cat with hepatic lipidosis?
enlarged hyperechoic liver
changes can occur in obese or diabetic cats
useful for diagnosing underlying diseases
how is a presumptive diagnosis made for hepatic lipidosis?
FNA showing lipid type vacuolation of the liver
alongside clinical signs, lab tests, & imaging
what is required to make a definitive diagnosis of hepatic lipidosis in cats?
biopsy for histology!
what electrolytes are you worried about in a cat with hepatic lipidosis?
hypokalemia - can lead to muscle weakness
hypophosphatemia - can lead to hemolysis
hypomagnesemia - can lead to muscle weakness
what makes up the initial supportive care for a cat with hepatic lipidosis?
IV fluids - account for dehydration, ongoing loss, & maintenance requirements
electrolyte correction
vitamin K
n-acetylecysteine
anti-emetics - maropitant or ondansetron
what is the maintenance fluid rate used for cats in this class?
40 ml/kg/day
what is Kmax?
0.5 mEq/kg/hr
how is nutrition approached in cats with hepatic lipidosis?
correction of protein is crucial!!! it is the most important of the macronutrients - feed a calorie dense food
aim to feed 30-40% of metabolizable energy as protein
give vitamin K first & place a feeding tube - need to avoid syringe feeding
why give a cat with hepatic lipidosis antioxidants?
oxidative damage plays an important role in feline hepatic lipidosis - beneficial
how is cobalamin supplemented for cats with hepatic lipidosis?
given when serum levels are <400 ng/L
give cyanocobalamin - 250 ug SQ once weekly for 6 weeks & then once monthly
also can be used as an appetite stimulant
why is l-carnitine used for cats with hepatic lipidosis?
shuttles the fatty acids to the mitochondrial matrix & increases hepatic utilization of fatty acids during weight loss
250 mg/cat PO every 24 hours
what are some negative prognostic factors for cats with hepatic lipidosis?
anemia, hypokalemia, & incurable underlying disease
T/F: cats can make a complete recovery with early & aggressive treatment
true
what is feline cholangitis? what are the 3 types seen clinically?
inflammation centered around the biliary tract with expansion into the parenchyma
- neutrophilic
- lymphocytic
- liver-fluke associated
why do we believe cats to be more sensitive to developing cholangitis/pancreatitis?
they have a shared duct between the pancreatic duct & bile duct entering the duodenum
what clinical signs are associated with neutrophilic cholangitis?
acute onset of illness - pyrexia, anorexia, vomiting, icterus
what clinical signs are associated with lymphocytic cholangitis?
chronic signs - lethargy/hyporexia that can wax & wane or be progressive
what signs are seen upon physical exam of a cat with cholangitis?
dehydration, icterus, pyrexia, cranial abdominal pain, & emaciation
what clin path abnormalities are seen in cats with cholangitis?
increased liver enzymes
hyperbilirubinemia
hyperglobulinemia
hypoalbuminemia
what is seen on hematology that is supportive of cholangitis in a cat?
neutrophilia - +/- a left shift, but less common with lymphocytic cholangitis
non-regenerative anemia
thrombocytopenia
what is seen on abdominal ultrasound of a cat with cholangitis?
findings consistent with inflammatory disease
hepatomegaly, bile duct dilation, & choleliths
how is a cholecystocentesis done?
use a right-sided transhepatic approach - get an FNA of the bile & look for the presence of bacteria & neutrophilic inflammation
what are some examples of different ways a liver biopsy can be performed?
needle biopsy
laparotomy
laparoscopy
how long do you treat a cat with antimicrobials for neutrophilic cholangitis?
4-6 weeks
what do you do for treatment if you have a cat with neutrophilic cholangitis that has a negative culture & doesn’t respond to antibiotics?
prednisolone!!!
what is triaditis?
syndrome encompassing concurrent inflammation of the liver, pancreas, & small intestines
how is RER calculated?
(30 X BWkg) + 70
70 X (body weight in kg ^0.75)
how is a feeding plan used for a cat with hepatic disease?
only feed 25% of RER on the first day & increase to 100% over 3-4 days dividing the daily ration into 4 meals fed over 10-15 minutes
T/F: cats commonly get combinations of chronic enteropathy, pancreatitis, & inflammatory liver disease
true
T/F: failure of a cat to respond well to prednisolone does not rule out small cell lymphoma
true
