high alt level in my cat

Hello, I'm new here and looking for any info or advice. About 15 days ago my cat Cecil had a issue were he wasn't eating or drinking at all. So we went to the vet for x-ray and bloodwork and the vet said Cecil's alt level was high. (Normal is 12-130). It turns out his alt level was 2,438. Is that even possible? My vet didn't seem surprised but everywhere I look for info I cannot find any that suggest it is common or crazy high. At that time Cecil was acting as his normal self aside from the fact he didn't eat that day we went to vet. He has been on three meds since. Denamarin, amoxi, and metronidazole.
Currently Cecil is eating, playing, and seems fine but im worried that once he's off meds problems may return. All other tests that day were fine, just the alt was off. Vet said its a infection and after meds he should be fine. Anyone have or hear of an alt test that high before? Could it be something more serious then a infection? Any help or info is greatly appreciated by Cecil and I. Thanks.

A few years ago one of my girls started to have a problem with an elevated ALT level that slowly and steadily went up to the high three hundreds and then suddenly to an incredible 2140. So yes, an unbelievably high number is possible. (Immediately she had a whole new round of tests and at that time the ultrasound finally showed what the problem was.)

If Cecil hasn't had an ultrasound yet I'd like to urge you to schedule one right away. You need the results of this very important test even if you're treating with medication.

I'd also like to urge you to ask for the fPLI test immediately to find out whether pancreatitis is involved in whatever is going on with your baby.

Thorough testing and early and aggressive treatment can make a very important, even life-saving difference with diseases that involve the liver so please insist on frequent blood work follow ups to make sure things are going in the right direction. (Your vet can choose to check the liver enzymes only unless there seems to be a need to include other values as well.) And continue with frequent blood work follow ups even after there is significant improvement.

I agree with everything Violet just suggested. You need to know the cause of this in order to treat it. Ultrasound shows much more than plain x-ray.

Thank you Violet for the reply and info about the other tests to have. I have a appointment at the vet this week and will be having bloodwork done as well as the other tests if I have the money for it all at that time. Unfortunately for me vets are crazy expensive and i'm laid off work. But rest assured Cecil will get the treatment he needs. Even if I have to sell everything I own.
Again thank you.