What is the primary method to diagnose heartworm disease in pets?

The primary method to diagnose heartworm disease in pets is through blood tests. These tests, particularly antigen tests, detect specific proteins produced by adult female heartworms. When a pet is infected, these proteins enter the bloodstream and can be identified through a simple blood sample, making it a reliable and effective diagnostic tool.

Blood tests are favored for several reasons: they can confirm the presence of the worms before clinical signs become evident, allowing for earlier treatment and better outcomes. In contrast, diagnostic methods such as X-rays may show changes in the heart or lungs caused by heartworms, but they can't definitively confirm the presence of the parasites. Urinalysis tests are not effective for diagnosing heartworm disease as they are designed to assess kidney function and urinary tract health. Likewise, a physical examination can reveal symptoms suggestive of heartworm disease, like coughing or lethargy, but it cannot confirm the infection without further laboratory testing. Therefore, blood tests remain the cornerstone for diagnosing heartworm disease in pets.