Whether it’s because your horse is ill or just for routine monitoring, sooner or later your veterinarian is likely to suggest a blood-chemistry panel. While correct interpretation of blood tests requires considerable experience and should only be done with your veterinarian’s input, a working knowledge of what these tests mean will help you understand his or her explanations.
We’re focusing on some of the common tests of organ function you’ll find on a chemistry panel, what they test for and the possible significance of the results. We discuss individual tests in our chart on pages 16-17, while chemistry panels typically include calcium, phosphorus and other electrolytes depending on the type of screen requested.
It’s important to realize that different laboratories may have slightly different normal ranges, but the normal ranges are generally included in the laboratory’s report, usually with abnormal results somehow highlighted to stand out.
Complete, sometimes called “super,” chemistry screens include amylase and lipase (pancreatic tests), triglycerides (of concern in some metabolic problems) as well as calcium, phosphorus, magnesium and the major electrolytes. If you were able to draw, process and transport the sample yourself, the cost at most labs would be around $40.
Large-animal panels that include the complete minerals/electrolytes and the tests on our chart, but leave out the less frequently elevated pancreatic enzymes and triglycerides, run about $28.
Your veterinarian’s actual charge for each test will also reflect overhead of personnel, supplies, handling and shipping, if he doesn’t have a laboratory with a courier service. Veterinarians and animal clinics that have their own laboratory equipment typically charge similarly to the state, university or commercial laboratories.
Shorter general-health panels, that either omit electrolytes and less commonly elevated enzymes or focus on electrolytes and minerals but don’t do the organ-function tests, generally cost between $20 and $30 (the laboratory fee without the added veterinarian cost). Many laboratories also offer special panels specifically for liver or muscle disease testing in the same price range.
Note: Most laboratories also offer combination packages of the chemistry panels plus CBC (red cell, white cell and platelet studies), or plus CBC and T4 (thyroid hormone). These combination packages offer savings on the CBC and T4 of from 10 to 20% compared to the price of running the individual tests of running the CBC test and T4 test alone.
Unless the veterinarian knows exactly what he or she is looking to find, the longer chemistry panels are most likely your best buy, because they increase the chances that any abnormalities will be found. In addition, the wider variety of chemistry tests will make it easier to sort through the possible causes of abnormalities, as you may note in our sidebar, ”Interpreting Tests Takes Skill.” However, the challenge in the interpretation of elevated values can’t be ignored and requires that you understand the tests.