Hello, thanks for your question today! I am Dr. Drew, and I am a licensed veterinarian. I'll be happy to help you in any way I can.
Albumin is a protein found in the blood,
and it can be low for a variety of reasons.
First, the total protein level must be checked, as there are other proteins besides albumin, which may be elevated,
Globulin, the most commonly measured protein other than Albumin, can be elevated due to inflammation, or some types of cancer,
and the albumin level will decrease in compensation for the high globulin level, in order to maintain an acceptable total protein level.
If that situation is ruled out, then we need to break this down into one of a few possibilities:
There's either not enough protein being eaten (unlikely with a good appetite),
Not enough protein being manufactured by the liver,
Not enough protein being absorbed by the intestine (usually there's diarrhea or soft stools in this case),
Or there's too much protein being lost from the body, either in the urine, or stool (see above).
If the urine has no significant amount of protein present, we can most likely rule out kidney problems as a source for low albumin.
I'd want to run a Bile Acids profile to see if the liver is functioning well, this is a blood test.
Ultrasound is a good test, to check for structural abnormalities in the internal organs,
but it doesn't tell us much about function.
both are important.
The next step would be an Endoscopy of the intestinal tract, with biopsies of the intestinal lining,
in order to determine if there's a problem preventing proper absorption.