Hepatic Dz Flashcards
General CS of Hepatic Dz
Depression, anorexia, WL, Icterus, ataxia
+/- hepatic encephalopathy
Diagnostic tests for hepatic dz
Hx, CS, Chem, UA, Fecal (parasites), fibrinogen (MDB)
Enzymatic (detect dz): GGT, ALP, GLDH, AST, SDH
Function tests: BR, BA, globulin, glucose, BUN, triglycerides, albumin
Hepatic US and bx (histopathology)
Tx therapy goals for Hepatic Dz (general)
Remove cause and tx dz (prevent more absorption)
Prevent ammonia production and absorption (gut)
Diet (↓ protein and ↑ carbs)
Supportive therapy (IV, analgesics, abx)
Plant species associated with pyrrolizdine toxicity (PA)
Ragwort, buttereeed, groundsel, rattlebox,
How do horses obtain PA toxicity?
Consumed when it’s only green forage available or in baled hay (unpalatable when fresh)
CS 14d after ingestion
CS of PA toxicity
Chronic progressive
Liver failure signs, WL, behavior, aimless wandering and pacing
Licking inanimate objects, blindness
Convulsions & coma then death
Pyrrolizidine Toxicity (PA) pathology
GIT absorption → detox in the liver → pyrroles → bind to protein and nucleic acid within hepatocytes →cross linked DNA → megalocytosis →die and replaced by fibrous tissue
Dx PA
MBD: ↑ liver enzymes and BA
Bx (confirming)
Chemistries + CBC: BA, SDH, triglycerides
Results of bx of a horse with ACUTE PA toxicity
Acute: periportal changes, moderate to severe centrilobular necrosis with hemorrhage
Results of bx of a horse with CHRONIC PA toxicity
Hepatocellular death in portal areas
Megalocytosis, fibrosis, biliary hyperplasia
Tx of PA toxicity
Remove source, prevent further absorption
IV fluids, NSAIDs
Stabilize membranes (antioxidants, Vit E)
Modified diet of a horse with PA toxicity
Low amounts of high-quality protein
Large amounts of complex CHO (no grain, grass only)
Other hepatic toxins
Phenylbutazone, flunixin, acetaminophen, salicylates and antifungals
@ high doses for long time
Parsacaris equorum (parasite)
Horses <2y (adults immune)
Burrows in SI → migrate through veins to liver, heart and lungs
CS of P. equorum
Young, dull dry hair coat, slow growth, +/- cough, nasal discharge
Dx P. equorum
Hx, signalment and fecal (>400 eggs found)
Tx of P. equorum
slow kill anthelmintics (fenbendazole)
Vitamin/ mineral
Fluids, NSAIDs, analgesics PRN
If colic: sx
Verminous hepatitis
Larval migration through hepatic parenchyma
Tx: NSAIDs (dead worms in body) and DMSO (10%)
Large strongyles
S. edentatus (liver and peritoneum)
S equinus (liver)
S. vulgaris
CS of large strongyles infestation
Poor performance, dull/ rough hair coat, diarrhea, WL, recurring colic, pot belly and stunted growth
What diseases cause equine hepatitis
Acute Hepatic necrosis (Theiler’s/ serum sickness)
Parvovirus and hepacivirus
Tyzzer’s
Cholangiohepatitis
Acute Hepatic Necrosis
Associated with vaccines and summer/fall
Limited to adult horses
Acute to subacute
CS of acute hepatic necrosis
Admin vx 1-3w before
Hepatic failure, anorexic, icteric, head pressing and sudden death
Parvo and Equine Hepacivirus
Cause acute inflammation or no CS and ↑ liver enzymes for a few weeks
Healthy carriers with no CS = reservoirs for infection
Differentiate via serology
Equine Parvovirus Hepatitis (EqPV-H)
Adult horses 4-12w post admin of vx
CS: lethargy, anorexia, jaundice, neurologic symptoms (HE)
What causes EqPV-H
Vx- infected blood products
Insect vector, nasal or fecal shedding
Equine Hepacivirus (EqHV)
Subclinical dz in adult horses with transient mild elevated hepatic enzyme
Causes chr. hepatitis and liver failure during PI
Cholangiohepatitis and Cholangitis
Acute liver failure: severe inflamm. of the biliary tract and parenchyma
What causes Cholangiohepatitis and Cholangitis
Duodenitis, intestinal obstruction, cholelithiasis, parasitism and neoplasia
CS of Cholangiohepatitis and Cholangitis
Mild, recurrent colic, inappetence, icterus, depression, HE, pyrexia
Chr: WL, head pressing and fever
Pathophysiology of Cholangiohepatitis and Cholangitis
Asc. bacterial infection via sphincter of Oddi (gram- rods)
E. coli, Salmonella, Actinobacter
Choleliths
Large colon displacement in adult horse and duodenal ulceration in foals
Dx Cholangiohepatitis and Cholangitis
MDB + US (swollen/ rounded edges + choleliths)
Liver bx: Neutros in portal triads and degenerate parenchyma + purulent exudate in ducts
Tx of Cholangiohepatitis and Cholangitis
Decompression PRN (colic)
Antimicrobials (4-6w) analgesics and dietary change (bland diet)
Prognosis of Cholangiohepatitis and Cholangitis
Good if no fibrosis
Guarded if HE, severe periportal or bridging fibrosis
Tyzzer’s Dz
Acute necrotizing hepatitis (fatal)
Foals 7-42d in good flesh, well-nourished
+/- sudden death w/o CS (progress rapid)
What causes Tyzzer’s Dz
Clostridium piliforme- motile, obligate intracytoplasmic gram- spore forming rod
In soil
Risk facts associated with Tyzzer’s Dz
↑ protein and CHO in diet (affects microflora) → pathogenic bacteria overgrowth
Stress, immunosuppressive drugs and antibacterials
Histopath for Tyzzer’s Dz
Foci areas of coagulative necrosis with infiltrate of neutros, macros and lymphos
Warthin-Starry or Diesterl’s silver stain
CS of Tyzzer’s Dz
Non-specific: comatose or dead
Lethargy, depression, fever and jaundice
+/- loss of suckle reflex
Necropsy for Tyzzer’s Dz
Hepatomegaly (1-5mm)
White foci scattered throughout parenchyma
Icterus and hemorrhage
Tx for Tyzzer’s Dz
None, glucose +supportive therapy
Guarded to poor (fatal)
Hyperlipemia and hepatic lipidosis
Metabolic dz of ponies, AMH, donkeys
Periods of negative energy balance and physiologic stress
Poor prog with hepatic signs
History associated with Hyperlipemia and hepatic lipidosis
Prolonged stress/ WL
Obesity and sudden ↓/ change in feed
Heavy pregnancy, late or early lactation
↓ quality feed + high energy demand
↑ energy demand + poor quality feed intake/ ↓ feed intake
Dx Hyperlipemia and hepatic lipidosis
CBC, chem and fibrinogen
BA >30, ↑ liver enzymes and triglycerides > 500 mg/dl
Grossly discolored serum/ plasma
Necropsy for Hyperlipemia
Liver and kidneys: pale, swollen and friable. Greasy texture
Histopath for Hyperlipemia
Fat deposits in the hepatocytes and bile duct epithelium
Hepatic sinusoids compressed and anemic
Nutritional support for Hyperlipemia
Reverses negative energy balance
Promotes endogenous insulin release
Inhibits fat mobilization
Hyperlipemia resolution
Resolves in 5-10d with tx and diet change
May not reverse in ponies and donkeys
If doesn’t resolve: hepatic fatty infiltration
Hepatic lipidosis dx
Obese pony, AMH, or lactating
Blood serum/ plasma: opalescent
US: rounded edges, compressed ducts and diffuse parenchyma
Chem: hepatic dysfunction
Histopath: fatty infiltration
Necropsy of Hepatic lipidosis
Swollen, pale, friable, cut surface
Nutmeg appearance and bulging
Tx of hepatic lipidosis
Remove underlying cause
IV fluids with electrolytes, dexmeth, dextrose
Reduce workload of liver: glucose IV
Inhibit fat mobilization form adipose tissue (insulin and glucose)
Cholelithiasis
Rare common biliary pathway dz
6-15y with icterus, abdominal pain that gets worse + pyrexia, depression and WL
Pathophysiology of Cholelithiasis
Sludging of bile
Colic + intestinal inflamm. : bacteria → bile ducts open→ asc. nidus → precipitation of bile
Dx Cholelithiasis
MDB
US: mult. hyperechoic lesions
Bx: fibrosis around intrahepatic bile duct (occlusion of common bile duct)
Tx of Cholelithiasis
IV fluids + electros
Antimicrobials, lactulose (if high ammonia), DMSO and diet
Euthanize if bad!
Prognosis of Cholelithiasis
Poor to grave: extensive/ bridging fibrosis, multiple choleliths + hepatic failure and atrophy and HE
Which drug is contraindicated with hepatic insufficiency?
Diazepam: enhance effect of GABA and exacerbate HE
When do you use HCO3-
Acidosis
If corrected to rapidly: ↑ blood ammonia, hypokalemia or alkalosis →↑ renal production of ammonia → ↑ diffusion of ammonia into CNS
What should horses avoid in their diet with hepatic dz?
Avoid alfalfa and legume hay
Hepaticencephalopathy
Benzodiazepine receptor antagonist- induces clinical and electrophysiologic remission of HE in human: flumazenil and bromocriptine (dopamine agonist)
Thiamine: reduce risk for neuropathies
Abx for hepatic dz
Abx: ceftiofur, penicillin and gentamicin
Aslike clover
Big liver syndrome
Chr. consumption
Irreversible liver dz associated with neurologic symptoms
