How will you diagnose a dog with heartworm disease?

Usually, I'm going to run a test called an ELISA test. It's a blood test that we run here in the office. It is screening for adult female worms, which are 90% of the worms that dogs are infested with, if not more. This test is also recommended yearly because it screens for some of the tick-borne pathogens, Lyme disease, Ehrlichia, and anaplasmosis, which are also essential to screen for in your dog. If the dog is positive, we will also continue to look at the blood, looking for baby heartworms to confirm that diagnosis. We look in the microscope for those, and you can see them wiggling. They look like tiny, wiggly worms.