Hepatic Disease - Equine Flashcards Preview

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Flashcards in Hepatic Disease - Equine Deck (50):
1

The liver accounts for what percentage of an adult horse's body weight?

1.6%

2

What are the functions of the liver?

- processing nutrients from food
- storing glucose, vitamins, and minerals
- maintaining immune function
- removing toxins from the blood

3

What percentage of the horse's total blood volume resides in the liver?

10%

4

How much of the liver must be damaged before there is abnormal function or failure?

70-80%

5

What are the general clinical signs of acute liver dysfunction?

- depression
- HE
- icterus
- colic
- anorexia

6

What is indicated by a high level of fibrinogen?
Low level?

high - inflammatory process

low - issues with production in liver

7

What is indicated by elevated bilirubin?

- liver failure
- bile blockage
- excess production

8

Which enzymes can be used to evaluate liver function?

SDH
ALP
AST
GGT

9

Which coagulation factors are produced in the liver?

I, II, V, VII, IX, and X

10

Where should the ultrasound probe be positioned to evaluate the liver?

right side, caudal to the lungs, in the 6th to 14th intercostal spaces

11

What are the possible causes of icterus/jaundice?

decreased excretion or increased production of bilirubin

12

What is photosensitization type 1?

primary photodynamic agent enters skin by ingestion

13

What is photosensitization type 2?

- accumulation of endogenous photodynamic agents
- congenital prophorias

14

What is photosensitization type 3?

hepatogenous secondary photosensitization
- phylloerythrin

15

What are the clinical signs associated with photosensitization type 3?

- erythema initially
- edema
- sloughing and exposure of subcutaneous tissue

16

How is photosensitization treated?

- eliminate photodynamic agent
- remove animal from sunlight
- treat as skin burn

17

What is hepatic encephalopathy?

- neuropsychiatric syndrome secondary to hepatic insufficiency
- CNS characteristics

18

What are the clinical signs associated with hepatic encephalopathy?

- frequent yawning
- abnormal behavior
- aimless wandering and foot stomping
- head pressing, circling, seizures

19

Describe the proposed pathophysiology of hepatic encephalopathy

- decreased branched-chain amino acids, and increased aromatic amino acids
- aromatic amino acids cross BBB into CNS
- increase inhibitory neurotransmitters
- increase GABA and L-glutamate
- imbalance of inhibitory and excitatory neurotransmitters

20

How is hepatic encephalopathy treated?

- eliminate underlying cause
- supplement with branched amino acids
- low protein, high carb diet
- avoid alfalfa
- supportive therapy

21

What is idiopathic acute hepatic disease?

- Theiler's disease or serum sickness
- most common cause of acute hepatitis and hepatic failure in horses

22

What are the possible causes of IAHD?

- viral infection
- tetanus antitoxin
- hypersensitivity type 3
- dietary factors
- pyrrolizidine alkaloid toxicity

23

What are the clinical signs associated with IAHD?

- abrupt presentation
- CNS signs
- yawning as early sign
- photodermatitis
- intravascular hemolysis
- weight loss and ventral edema

24

What are the hematology/chem features of IAHD?

- elevated bilirubin, AST, SDH, and GGT
- increased bile acids
- decreased BUN
- hyperammonemia
- prolonged clotting time

25

What are the histopathologic features of IAHD?

- hepatocellular necrosis
- portal accumulation of mononuclear cells and neutrophils
- proliferation of bile ductules

26

Which disease results in a "dishrag" liver?

idiopathic acute hepatic disease (IAHD)

27

What is choledocholithiasis?

stone found in the common bile duct

28

What is hepatolithiasis?

presence of calculi in the intrahepatic bile duct

29

What are the possible causes of cholelithiasis?

- ascending biliary infection or inflammation
- parasites (ascarids)
- biliary stasis/reflux
- changes in bile composition
- foreign body

30

What are the clinical signs associated with cholelithiasis?

colic with pyrexia and icterus

31

What are the hematology/chem features of cholelithiasis?

- neutrophilic leukocytosis
- increased liver enzymes
- increased bile acids and bilirubin
- hyperammonemia
- prolonged clotting time

32

What are the histopathological features of cholelithiasis?

- periportal fibrosis
- bile duct stasis and hyperplasia

33

Which bacteria can be present with cholelithiasis?

Bacteriodes vulgtus and E. coli

34

How is cholelithiasis treated?

- antimicrobials, fluids, anti-inflammatories, DMSA, dietary management
- choledocholithiotomy +/- choledocholithotripsy

35

What are the histological and gross features of chronic active hepatitis?

- infiltration of inflammatory cells into portal areas, necrosis, and fibrosis
- liver is firm, and often pale brown-green

36

What are the clinical signs associated with chronic active hepatitis?

- progressive weight loss
- intermittent fever
- icterus
- moist exfoliative dermatitis
- necrotic leathery skin at coronary band

37

How is chronic active hepatitis treated?

- supportive care
- corticosteroids
- antimicrobials
- anti-inflammatories
- Colchine

38

What is the action of Colchine?

inhibits production of collagen and macrophages/cytokine-induced inflammation

39

Describe the pathophysiology of pyrrolizidine alkaloid toxicity

- alkaloids metabolized in liver to pyrroles
- cross links DNA and causes antimitotic effect
- hepatocytes die and are replaced by fibrous tissue
- inhibition of enzymes and protein synthesis
- veno-occlusive

40

What is found on liver biopsy with prryolizidine alkaloid toxicity?

- fibrosis
- bile duct proliferation
- megalocytosis

41

What is Tyzzer's Disease?

- bacterial hepatitis in foals
- rapidly fatal

42

What organism is responsible for Tyzzer's disease?

Clostridium piliformis

43

What are the clinical signs associated with Tyzzer's disease?

- sudden death
- fever, depression, anorexia, diarrhea
- icterus, hypoxia, tachypnea, seizures

44

What is found on hematology/chemistry with Tyzzer;s disease?

- elevated liver enzymes
- severe hypoglycemia

45

How is Tyzzer's disease diagnosed?

PCR
post-mortem is the only definitive dx
- Warthin-Starry Stain

46

How is Tyzzer's disease treated?

- aggressive supportive therapy
- penicillin, tetracycline, erythromycin

47

What are the possible causes of hepatic failure in foals?

- pre-colostral iron fumarate toxicity
- perinatal herpesvirus
- leptospirosis
- cholangitis associated with duodenal ulcers
- ascarid migration
- portosystemic shunt
- hepatotoxicity (neonatal isoerythrolysis)

48

What is the treatment for abnormal behavior from hepatic disease?

Xylazine
- avoid diazepam

49

What are the methods for decreasing blood ammonia?

- mineral oil, oral neomycin
- oral lactulose
- Metronidazole

50

What are the terminal signs of hepatic disease?

hemolytic crisis
severe hepatoencephalopathy with fibrotic liver