21. acute liver disease of dogs, acute hepatic failure Flashcards
what should be mentioned
acute hepatic failure
hepatotoxicosis:
- paracetamol
- phenobarb
- phenytoin
- potenciated sulphonamides
infectious
- viral: rubarth, herpes
- bacterial. leptospirosis, tyzzer, helicobacter
- mycosis
- protosoa
- parasites
what types of hepatotoxicosis do we have
4 Ps :) paracetamol phenobarbital potenciated sulphonamides phenytoin
acute hepatic failure - what is it
not a specific diagnosis, not a disease
sudden, severe insult involving 70-80% of the liver parenchyma
Severe liver dysfunction, necrosis, degeneration
cause usually unknown
toxins
crlinicak signs of AHF
acute onset
anorexia, depression, dehydration
vomit, PD, icterus, fever, abdominal pain
laboratory findings in AHF
ALT: alanine trasnsferase very increased
ALKP: increased (sign of cholestasis)
Br: increased
APTT, PTT: increased
hepatotoxicosis in general
liver is very sensitive
intrinsic effect: reproducible, dose dependent or directly toxic (paracetamol, xylitol)
idiosyncrasic effect: unique, can’t recalculate it, even below therapeutic dose (phenobarbital, itraconazole)
paracetamol toxicosis etiology
quick depletion of glutathione stores
toxic metabolites -> oxidative injury
erythrocytes: methemoglobinemia
hepatocytes: necrosis
dose dependent toxicosis
paracetamol clinical signs
cyanosis, tachypnoea, dyspnoe
brown blood :(
paracetamol lab findings
hemolytic anemia, methemoglobinemia, brown blood
ALT increase
Br increase
hemoglobinuria
paracetamol treatment
NAC - n-acetylcystein = ANTIDOTE <3
SAMe for support
silimaryn, C vitamin
fluid, electrolyte etc
phenobarbital toxicosis
idiosyncratic reaction acute necrosis, hepatitis, cirrhosis ALP, ALT increase therapy: stop drug admin SAMe for support
phenytoin
very hepatotoxic - don’t use
acute or chronic hepatitis
its metabolite - primidone is also very toxic necrosis , lipidosis
potenciated sulphonamides
idiosyncratic effect, common in dogs
missing gene that codes for enzyme that breaks it down
T cell immune response
thrombocytopenia, fever, polyarthropathy
treatment of liver toxicosis
stop drug antidote if exist gastric lavage, charcoal stabilize - fluid, electrolyte antioxidant treatment and refilling glutathione stores - NAC, SAMe - E vitamin, silymarine
viral hepatitis - rubarth - what is it?
hepatitis contagiosa canis - Rubarths - canine adenovirus
exposure-viremia-lymphoid tissue - cytotoxic injury
acute hepatic necrosis, gall bladder edema
