NUTRITION
How to handle abnormal liver enzyme activity in dogs
(ALT, AST, GGT and ALP)
No clinical signs
Investigate for non-
hepatic disease and
drugs as cause
Clinical signs
Consider trial therapy,liver
support or antibiotics
Recheck liver enzymes in
6-8 weeks
Enzyme
activities
abnormal
Enzyme
activities
normal
Measure bile acid
concentration
Aetiology
identified
Aetiology
not
identified
Icterus, ascites,
hepatic encephalopathy
or hepatic mass
Treat primary
non-hepatic
disease first
Recheck liver enzyme
activities at a later date
Persistent abnormal liver enzyme activities or
abnormal bile acid concentrations
If the patient is symptomatic:
When I have a sick dog with abnormal liver enzyme
activities, the first thing I do is look for a primary, non-
hepatic cause. Could it have gastrointestinal (GI) dis-
ease, pancreatitis, heart failure, septicaemia or some
other underlying disease?
If I identify a non-hepatic disease that could be the
cause, I treat that first. If, on the other hand, I can’t find
anything, I work up the patient’s liver.
Here's my list of liver workup considerations:
• Abdominal radiographs
• Serum bile acid concentration (in non-icteric pa-
tients)
• Abdominal ultrasound
• Hepatic fine-needle aspirate and cytology
• Coagulation profile
• Liver biopsy (via ultrasound-guided needle biopsy,
surgery or laparoscopic biopsy)
If the patient is asymptomatic:
Determining what to do with an asymptomatic dog is
more complex. First, I perform a full physical exam to
make sure I’m not missing some occult disease, such
as an endocrine or metabolic disease. I then check
the patient’s drug history, as certain drugs (such as
cortico