Microfilariae are larval forms of heartworms, not mature heartworms. The mature heartworms are the ones that block blood flow in animals with dirofilariasis. Hence, the statement is false.
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Microfilariae are larval forms of the heartworm, not the mature ones that block blood flow. It is the mature heartworms that cause cardiovascular issues when they reside in the heart and pulmonary arteries. Therefore, the statement is false. ;