Do all dogs with shunts have high bile acids?
Dog with shunts will almost always have high bile acids 2 hours after eating, and usually at least 95% of dogs will have high bile acids after a 12 hour fast. Samples are taken at both time periods ("fasting" or "preprandial", and "fed" or "postprandial") for several reasons. Some dogs normally release bile acids in the middle of the night and therefore naturally have a higher than normal fasting sample. Other dogs may have fat in their blood ("lipemia") after eating, which can interfere with the test. If only one blood sample can be obtained, it is best to take it 2 hours after eating.
Portosystemic Shunts FAQ
He does not have preprandial high bile acids, so there is a 95% chance that there isn't a large shunt. There is a very good chance that it is MVD. With a post that high though, a large shunt really should be ruled out. I would do further testing. Because he isn't growing as well as he should be, I'd go to an internist. They may try to talk you into an ultrasound but they are only 60-80% accurate for diagnosing shunts. They are a good tool if you are looking at the size of the liver and if there are secondary bladder stones though.
High protein may make the results high but not that high.
Medications can skew the results.
Had he had any heartworm med or flea med one week before the test?
Had he had any vaccines for about a month before the test?
His diet will need to be changed if the bile acids are up because of ls or mvd.
It wouldn't hurt to put him on canned L/D until you are sure that everything is okay.
You could also put him on low protein and supplements for a month and retest but that number seems a bit high to do that (my opinon only). L/D isn't really a good food for puppies either because it is so low in protein.