Exam 3: Equine Hepatic Dz Flashcards
Common liver diseases with adult and foals
- Adults = Theiller’s disease, cholangiohepatitis, chronic active hepatitis, pyrrolizidine alkaloid toxicities
- Foals = Tyzzer’s, EHV-1, sepsis, hepatic abscess
Clinical signs of equine hepatic disease and common associated diseases
+ COMMON = vague signs like weight loss, ADR (chronic active hepatitis)
+ Jaundice (cholangiohepatitis)
+ Photosensitization, seasonal (toxic)
+ Hepatic encephalopathy, seizures, mental alterations (Theillers in adults, Tyzzers in foals)
What happens with fasting in horses?
Can see a mild hyperbilirubinemia (unconjugated) if off feed or anorexic
Equine hepatocellular enzymes (2)
1) Most helpful = SDH = hepatocyte SPECIFIC
2) AST, can also be elevated with musculoskeletal dz
- SDH = hospital setting, doesn’t keep for long
- ALT = not helpful in horses
Equine cholestatic enzymes (2)
1) GGT: SPECIFIC, easiest and most helpful, may help you gauge disease progression and treatment efficacy
2) ALP = not specific (increased with bone, placenta, intestines, etc)
What is the ONLY condition that produces a conjugated hyperbilirubinemia?
Hepatobiliary disease like cholangiohepatitis (not hemolytic dz)
Most helpful biochem test for equine liver disease
Serum bile acids - doesn’t require fasting
Equine hepatocellular enzymes (2)
1) Most helpful = SDH = hepatocyte SPECIFIC
2) AST, can also be elevated with musculoskeletal dz
- SDH = hospital setting, doesn’t keep for long
- ALT = not helpful in horses
Equine cholestatic enzymes (2)
1) GGT: SPECIFIC, easiest and most helpful, may help you gauge disease progression and treatment efficacy
2) ALP = not specific (increased with bone, placenta, intestines, etc)
What is the ONLY condition that produces a conjugated hyperbilirubinemia?
Hepatobiliary disease like cholangiohepatitis (not hemolytic dz)
Most helpful biochem test for equine liver disease
Serum bile acids - doesn’t require fasting
Dx? depression, somnolence (drowsiness), mania, hyperexcitability, seizures
> Hepatic encephalopathy due to hyperammonemia
- Associated with fulminant acute or chronic liver failure = POOR prognosis
- Non-hepatic = idiopathic (concurrent GI disease), Morgan weanlings (heritable urea cycle defect)
When does Theiller’s disease most commonly occur?
Late summer, early fall (DDx: arthropod viruses like WNV, EEE, WEE)
Common hypothesis for causes of Theiller’s disease
Recent tetanous antitoxin administration (last 4-6 weeks) to commercial equine plasma (NOT NECESSARY)
*Thought to be viral = flavivirus (bloodborne)
Common clinical presentation of Theiller’s disease
Adult with acute onset of signs of hepatic encephalopathy or jaundice
Dx of Theiller’s disease
- History, time of year, clinical signs
- Chem = VERY HIGH SDH, AST, mild GGT/ALP
+/- Hyperammonemia - Hypoglycemia
- Metabolic acidosis
- Low BUN, low albumin
**Liver biopsy
Tx of Theiller’s dz
- Sedation
- Hydration = IV fluids = strong alkalizing ions (bicarb) and dextrose
- K+ in fluids
- Oral neomycin, metronidazole, lactulose
- Later = colchicine, prednisolone (anti-fibrotics)
Why don’t we use LRS with liver disease tx?
Liver patients can’t clear the L-lactate that is normally metabolized by healthy patients
Common clinical presentation of Theiller’s disease
Adult with acute onset of signs of hepatic encephalopathy or jaundice
Cause and diagnosis of chronic active hepatitis
- Path: inflammatory disease with progressive fibrosis (thought to be autoimmune)
- Dx: U/S guided biopsy (unusual to see U/S changes), histo that is lymphoctyic and plasmacytic, periportal fibrosis
Chem findings with chronic active hepatitis
Cholestatic»_space; hepatocellular