Lecture 24 3/31/25 Flashcards
What are the components of a liver assessment?
-physical exam
-blood work
-ultrasound
-liver biopsy
-right flank laparotomy
What finding on physical exam is most indicative of a liver issue?
icterus
Which measurements on blood work can provide an indication of liver function/health?
-AST
-SDH
-GGT
-bilirubin
-bile acids
-metabolism products (GUAC)
-PT/factor 7
What is the normal presentation of the liver on ultrasound?
-homogeneity with spaces indicating the vessels
When should a liver biopsy NOT be done for suspected liver issues?
when there is concern over whether the animal can effectively clot
What are the etiologic agents of liver abscesses?
-Fusobacterium necrophorum
-Trueperella pyogenes
What are the characteristics of liver abscesses?
-most prevalent in cattle on high energy diets; feedlot, dairy, show
-found in around 20 to 30% of animals at slaughter
-economic impact is derived from poor feed conversion, poor production, and condemnation of affected livers
What are the long terms sequelae of liver abscesses?
*erosion of the abscess into the caudal vena cava and systemic shed of septic emboli, leading to:
-vegetative endocarditis
-caval syndrome/embolic pneumonia
-renal infarcts
How do liver abscesses occur?
-damage to rumen wall liberates opportunistic pathogens into portal bloodstream
-bacteria first arrive at the liver, where they colonize and damage the parenchyma
-colonizations can expand into liver abscesses
What are the clinical signs/presentation of liver abscesses?
-range in size from pinpoint to softball sized
-can be singular or multiple
-animals may be symptomatic/only find abscesses at slaughter
-reduction in feed intake
-poor production
How can liver abscesses be diagnosed on ultrasound?
areas of heterogeneity that indicate the presence of an abscess/abnormal structure
What are the characteristics of liver abscess treatment?
-very unrewarding to treat
-can provide long term antibiotics
-percutaneous drainage can be attempted
How can liver abscesses be prevented?
*in-feed antibiotics
*vaccination
-reduces number or size of lesions
-prevents condemnation
*bunk management
-consistent feeding
-well balanced rations
-adequate bunk space
What are the characteristics of black disease?
-infectious necrotic hepatitis
-caused by Clostridium novyi type B
-gram-pos. spore-forming rod
-acute hepatitis in ruminants, especially sheep
-preceding liver injury creates anaerobic lesions
-most commonly associated with Fasciola hepatica
What are the consequences of the Clostridium novyi type B alpha and beta toxins on the body?
-damage to neurons
-vascular endothelium damage
-acute renal necrosis
-toxic shock
-sudden death
What are the clinical signs of black disease?
*sudden death
*signs of toxemia
-isolation
-fever
-malaise
-anorexia
-resp. distress
What are the findings on necropsy in black disease?
-rapid autolysis of liver and/or kidneys
-black hemorrhagic necrosis of liver
How can black disease be diagnosed?
-impression smears
-culture and toxin ELISA
What is the treatment for black disease?
high doses of penicillin or oxytet
What are the prevention steps for black disease?
-vaccination with the 7 way clostridial vx. in fluke-endemic areas
-strategic liver fluke treatment/prevention
-burn or bury affected carcasses to limit pasture contamination
What are the characteristics of bacillary hemoglobinuria/red water disease?
-caused by Clostridium novyi type D
-gram-pos. spore forming rod
-acute hepatitis in ruminants, especially cattle
-preceding liver injury creates anaerobic lesions
-most commonly associated with Fasciola hepatica
-toxin causes liver and RBC lysis
What are the consequences of the Clostridium novyi type D beta, zeta, and theta toxins on the body?
-intravascular hemolysis***
-icterus
-hemoglobinuria
-death
What are clinical signs of bacillary hemoglobinuria/red water disease?
*sudden death
*signs of toxemia
-isolation
-fever
-malaise
-anorexia
-resp. distress
-edema
*intravascular hemolysis
-icterus
-acute anemic crisis
-hemoglobinuria
What is the treatment for bacillary hemoglobinuria/red water disease?
-high doses of penicillin or oxytet
-blood transfusion
