Hepatic Disease - Equine Flashcards
(50 cards)
The liver accounts for what percentage of an adult horse’s body weight?
1.6%
What are the functions of the liver?
- processing nutrients from food
- storing glucose, vitamins, and minerals
- maintaining immune function
- removing toxins from the blood
What percentage of the horse’s total blood volume resides in the liver?
10%
How much of the liver must be damaged before there is abnormal function or failure?
70-80%
What are the general clinical signs of acute liver dysfunction?
- depression
- HE
- icterus
- colic
- anorexia
What is indicated by a high level of fibrinogen?
Low level?
high - inflammatory process
low - issues with production in liver
What is indicated by elevated bilirubin?
- liver failure
- bile blockage
- excess production
Which enzymes can be used to evaluate liver function?
SDH
ALP
AST
GGT
Which coagulation factors are produced in the liver?
I, II, V, VII, IX, and X
Where should the ultrasound probe be positioned to evaluate the liver?
right side, caudal to the lungs, in the 6th to 14th intercostal spaces
What are the possible causes of icterus/jaundice?
decreased excretion or increased production of bilirubin
What is photosensitization type 1?
primary photodynamic agent enters skin by ingestion
What is photosensitization type 2?
- accumulation of endogenous photodynamic agents
- congenital prophorias
What is photosensitization type 3?
hepatogenous secondary photosensitization
- phylloerythrin
What are the clinical signs associated with photosensitization type 3?
- erythema initially
- edema
- sloughing and exposure of subcutaneous tissue
How is photosensitization treated?
- eliminate photodynamic agent
- remove animal from sunlight
- treat as skin burn
What is hepatic encephalopathy?
- neuropsychiatric syndrome secondary to hepatic insufficiency
- CNS characteristics
What are the clinical signs associated with hepatic encephalopathy?
- frequent yawning
- abnormal behavior
- aimless wandering and foot stomping
- head pressing, circling, seizures
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
How is hepatic encephalopathy treated?
- eliminate underlying cause
- supplement with branched amino acids
- low protein, high carb diet
- avoid alfalfa
- supportive therapy
What is idiopathic acute hepatic disease?
- Theiler’s disease or serum sickness
- most common cause of acute hepatitis and hepatic failure in horses
What are the possible causes of IAHD?
- viral infection
- tetanus antitoxin
- hypersensitivity type 3
- dietary factors
- pyrrolizidine alkaloid toxicity
What are the clinical signs associated with IAHD?
- abrupt presentation
- CNS signs
- yawning as early sign
- photodermatitis
- intravascular hemolysis
- weight loss and ventral edema
What are the hematology/chem features of IAHD?
- elevated bilirubin, AST, SDH, and GGT
- increased bile acids
- decreased BUN
- hyperammonemia
- prolonged clotting time
