How does my veterinarian decide which lab tests to order for my dog?

Again, what the dog presents for will dictate what we have to do. And not to be repetitive, but on wellness visits, yearly checkups, heartworm tests, stool samples, and maybe even some wellness blood work, which is a CBC chem. Those are the most common. If you bring an animal in that presents for PU/PD, drinking a lot of water, urinating a lot...maybe they’re losing weight or dehydrated, then, no. My focus goes more to diabetes, hyperthyroidism, kidney failure, those kinds of things. So I'm much more inclined to get CBC chemistry and urinalysis on those animals. So again, it just depends on what they're presenting for, how sick they are, what their clinical signs are. All of that is going to dictate what tests we potentially run.

This is a very general question, but if your dog was coming in for a well-check, we would routinely do a yearly heartworm test, which is a blood test. If they're coming in sick, we may want to look internally at what's going on with them to determine what might be causing that. If they're vomiting, we can look at a blood test to look for pancreatitis. There are many tests that we can do to determine what might be going on.

We decide what labs may be needed for certain patients based on age, physical exam, and if they're having any symptoms. For instance, if I have an overweight middle-aged lab that we're having trouble getting some weight off, I'm probably going to have a blood test that includes a thyroid test. Our thyroid has a lot to do with our metabolism, and unfortunately, labs commonly get hypothyroidism or low thyroid, and that can have an effect on their metabolism. It's really going to be based on what I find in my exam. On the other hand, cats go the absolute opposite direction as they get hyperthyroid so their metabolism ramps up, and then all of a sudden, these cats are eating everything in sight and dropping weight like crazy. So if I have an older cat that's doing that, we're also going to check their thyroid and I'll be surprised if we don't see an elevated thyroid. It's based on the physical exam and on talking with the owners about what the symptoms or the clinical signs are, but we tailor each individual lab profile according to what is appropriate for that patient.

The decision on which tests to run depends on the individual dog. For a healthy pet, we'll run a different set of tests than for a sick dog. The tests for a sick dog will be determined by the symptoms we're seeing and the specific needs to establish a diagnosis. Sometimes, the initial test results may lead us to more testing once we have a clearer picture of the direction we need to go. If we have a healthy pet and we run a test, our hope is to get all normal results. However, if that doesn't happen, then we realize we have something we need to treat.