This nematode is common, found throughout the mid-Atlantic United States, but its transmission is not limited to warm months. They live within the dog's subcutaneous connective tissues. The microfilariae have a distinguishing cephalic hook, a blunt anterior end, and, in formalin fixed specimens, a 'button hook' tail. They are carried by vector fleas of the genus Ctenocephalides .
Development requires about ten days.
These ARE NOT clinically significant, although they may give elevated eosinophil and leukocyte counts. Its importance, however is its tendency to cause false positives in tests for circulating D. immitis microfilariae. They are easily distinguished by their staining patterns with acid phosphatase. While Dipetalonema stains realatively evenly, Dirofilaria concentrates the acid phosphatase in two regions. Acid phosphatase-stained microfilaria of Dipetalonema reconditum.