Like all bloodwork "high" liver values tend to be dependant on what OTHER values look like. That's not a cop-out answer - it's true. But it makes it complicated.
The ALT and AST often "pair up" in MY experience (Billy and Tink *both* can run high there -- not astronomically high but well over 'norm';) In Tink's case, in particular, it tends to be a bile duct build-up HOWEVER, that's usually the diagnosis of my holistic vet (and after a short course of dandelion herb - which is typically used for bile duct problems -- the values zoomed right straight back down to where they should be).
Billy's little escapade with the quarter/? Boy howdy -- HIGH liver values?? oh yeah -- and all of them pretty danged high.
Now that's where the "rub" is -- Most bloodwork gives you 'values' -- like (reading from Billy's newest one in front of me) his AST is 52 -- it *should be* 15 - 66. (the other day it was like 729 !!!!
NO DECIMAL THERE -- yeah -- today it's 52 ... Monday it was SEVEN HUNDRED TWENTY NINE.
Next one -- the ALT -- 921 in this reading ... Monday it was 2754.
There are like 5 "liver values" -- there's no real rhyme nor reason to those of us "who ain't gotta clue" but the norms run from low numbers like 1-2 (for GGTP) to in the low hundreds for like ALT. In other words, it would FEEL easier to us if they were all 1-25 and anything over ... 40 was "dangerous"?? But it just isn't that way (and I'm not even going to pretend to understand ANY of them in depth.)
However -- when you read the report usually there are four columns:
Test Requested Results Reference Range Units
So for Billy's
Test Requested: AST is under that
Results: 52 is under that (today)
Reference Range: 15 - 66 (meaning under 15 is gonna be noted as (LOW) and over 66 would be (HIGH)
Units: U/L (again, I've no clue -- some are in milligrams, etc.)
The scarey thing to the lay person as you look down thru them -- you see these notes (HIGH) or (LOW) after a number in the results colum -- and that's where it's easy to panic -- except a lot of these values have to be considered as part of a ratio or "this is only bad if ____ is low or high"
But then as you can see -- Monday Billy's looked astronomical in places -- but that ALT that was almost 3000?? All by itself it may not have been as "bad" as one of the others taken in conjunction with everything else.
Ok -- I say all that to say this -- TYPICALLY if it's just something like the AST and ALT -- that could be a number of things -- it could even be a temporary toxin (like heartworm tablet, application of something like Revolution, etc.) or the dog ate snow that fell off a roof (which DOES have toxicity to it *remembering the toxic way my crew reacted to the new roof 2 years ago*).
If this is an "only two skewed values" thing -- I'd hate to see the vet order a ton of tests just for that. I'd want to ask what and why, and I'd also be wanting to compare notes of what may have been in his environment lately.
Then again -- me being the type who has annual bloodwork done on my dogs anyway cos they're all "special" -- but this is how you begin to ESTABLISH a 'baseline' -- so the next time you run bloodwork (which may need to be in a couple of months with this dog UNLESS there is some clinical sign showing that says "We've got a PROBLEM here we need to address!!";).
Usually I *ask* for bloodwork for reasons like nausea, undigested food in the gut thrown up 6-8 hours later, lethargy, strange symptoms or behavior (particularly a huge "change";) or anything weird or spooky that we can't just outwardly determine -- OR if you suspect a particular liver, kidney, blood, pancreatic, etc. problem.
Before I jumped on the vet for wanting to do tests, my way would be to ask "why? Whatcha thinking this might be and ... do we have sign to suspect that?" It's Russian Roulette to categorically tell a vet "no" to tests -- particularly if you have any trust in them, or if there are some specific signs that you went to that vet FOR. ****OR**** if you went in for a well dog/senior visit and the vet suggested blood work (which they **should** at that point).
Like part of the thyroid panel -- some blood values can go up and down with the wind ... so you're looking for causes or trends or "reasons". But then you put all that together with the vet's reputation -- does this guy always suggest a ton of "tests" just in case? Or is he seen as really intuitive and good?
The liver filters blood (similar to but different from how the kidneys do) so high liver values are "toxins" in the body. TYPICALLY you don't even know there *are* high liver values unless you happen to catch them on a chance blood panel OR if the dog begins to show things like nausea (liver toxins shunt to the brain and make them *feel* sick to their stomach). You might **suspect** liver issues (particularly if you're holistically minded) if you are treating something like a skin problem, there is NO thyroid issue you can find but you just can't get resolution of that skin problem -- or some other besetting "problem" that's just being a pain in the butt.
Now if ALL the liver values were way whacked out that's different (like with Billy-meister) but just a couple?? It's not an easy "point to" thing to say "Oh that's ___________"
I hope that was explanation enough to "help" but not so much that it was confusing.