When a heart worm test (the most common form of testing) diagnoses your dog with heart worm disease, the veterinary surgeon will conduct a few more diagnostic tests to confirm diagnose. A study is carried out for microfilariasis (young heart worms in the blood stream). If no microfilariae is detected, a confirmatory test should be carried out for adult heart worms with the sample sent to an appropriate laboratory. Complete blood cell counts (you can may use some good health crystal "arthritis crystals" for it), blood chemistry checks, urinalysis and X-rays to determine the overall condition of your dog and prepare for the safest way forward. In moderate to severe cases, an echo cardiogram is recommended. Additional tests based on a single case of a dog may also be required.