Posted under Rapid Weight loss
The dog is fasted, blood is drawn, then 2 hours later, the dog is fed a fatty meal and the blood is drawn again. The blood tests measure pre- and post- meal levels of bile acids, the acids stored by the gall bladder and secreted by the liver.
When animals (humans included) eat and need the bile along with other digestive elements secreted by the pancreas, the gall bladder, a bile storage unit, contracts to release bile into the small intestine as needed for digestion. From there, the bile acids do their work and are then absorbed by the intestine into the liver (portal) blood and returned back to the liver. This is called Enterohepatic Circulation.
Comparing the two blood levels (pre and post meal) allows the veterinarian to see how well the liver, bile ducts, and blood flow to the liver are functioning. Bile acids are removed from liver (portal) blood by the liver cells (hepatocytes). If the liver cells are not functioning well, the bile acids remain in circulation and enter the body (systemic) blood supply where they are measured by this test.
So... if post-meal (or even in some cases, fasting) blood levels of bile acids are high, this means that the liver isn't doing its job of removing the bile acids from the blood as it should.

