A bile acid test is a test that allows you to find out how well your dog’s liver is performing and functioning, and if their bile acid levels are outside of the normal parameters, which can cause a range of different health problems.
Unlike enzyme testing, a bile acid test does not determine liver damage or inflammation, but is instead useful to find out if your dog’s liver is functioning normally, or if there are any problems that may require special management or correction.
Bile is an important digestive element that is produced by the dog’s pancreas, and then stored in the gall bladder to be released into the small intestine in order to digest food. As an acid, bile works to break down the fat portion of food as part of digestion, and then the bile is reabsorbed by the walls of the intestines and deposited back in the liver.
The liver in turn removes bile acid from the blood and sends it back to the gall bladder, and the whole cycle begins again.
However, if the dog’s liver cells are damaged or unable to function properly, the liver is unable to remove the bile deposited within it effectively, causing it to remain in the bloodstream.
Identifying an abnormally high concentration of bile acid within the bloodstream is ergo a highly effective way to identify potential liver problems in the dog, by means of interpreting the symptomatic high blood: bile ratio.
An abnormally high level of bile acid in the blood can indicate a range of different health problems ranging from pancreatitis to Cushing’s disease to cancer of the liver, and so the first step to successful management or control of such conditions often begins with bile acid testing.
Bile acid testing is most useful when performed on puppies, as identifying an anomaly or problem early on allows your veterinarian to take control of the relevant condition and correct or manage it before it worsens and may become harder to treat, or even impossible.
Problems with the liver and digestive system can be hard to definitively pinpoint, as internal problems such as these usually come accompanied by a wide and varied range of symptoms that can present quite differently from dog to dog.
Bile acid testing may be recommended as part of a wider panel of tests if your puppy isn’t thriving, has problems gaining or maintaining condition or otherwise appears to be unwell from a young age, and also for smaller breeds of dog such as the Yorkshire terrier that may have higher than usual risk factors for hepatic microvascular dysplasia.
In order to have your dog or puppy’s bile acid levels tested, you will need to book an appointment with your vet in the morning and then leave them at the clinic for a few hours before picking them up later, as following the test through takes a few hours to perform.
The process for the test involves fasting the dog (usually overnight) and then taking a blood sample from them after they have fasted and their stomach is empty, then giving them a meal that is high in fat and allowing it to digest for a couple of hours, before the blood test is repeated.
The bile acid levels of the two different blood samples are then compared, and if the level of bile acid within the blood is found to be higher than normal, this can indicate a liver problem in the making, which can then be investigated further.
Unless further investigation that requires an inpatient stay is indicated on the day of the test, your dog will usually be returned to you the same day.
Taking a pre and post meal blood sample is important in order to allow your vet to measure the blood’s bile acid at every stage of the digestive process, and the meal given needs to be high in fat because bile acid is required for the digestion of fats.
In healthy dogs, bile acid should be extracted from the blood after it has done its job of helping to digest fat, but if the liver is not performing this role properly, the blood’s bile acid level will remain high throughout the duration of the test, and not drop back down to normal parameters.
Generally, a high bile acid level after the meal indicates a problem, but in more serious presentations, the fasting bile acid levels of the dog may be abnormally high too. There is no set scale that works across the board in terms of a normal and abnormal range, and each laboratory that interprets the test will have their own system of measuring the results; ergo, like for like comparisons between different dogs or between the same dog being tested by two different labs is not possible.
Whilst one of the main concerns for vets and dog owners whose dogs have abnormally high bile acid levels is the potential of the dog being diagnosed with liver shunt, liver shunt in itself does not necessarily cause the elevated test results, but rather can help in the condition’s diagnosis. Liver shunt can be caused by a poorly functioning liver, rather than leading to the liver functioning poorly-and it is important to ensure that you understand the test results and that you are happy with your vet’s explanation of the test’s results and how to go forwards after testing, depending on the condition or concern revealed by the test.