Human Diroflaria Immitis

Has anyone ever heard of anyone having this? My husband has two nodules one on each side of his lungs, he is also a 3-year Pancreatic Cancer survivor. He had a PET Scan in February, which came back Negative, the Pulmonoligist says since his one nodule was 9.6 mm, that if there was Cancer there it should have shown up, so now 2 months later the one nodule is 1.cm, and the other is also slightly bigger, but these nodules are not calcifying as they should if it were an infection. These nodules were noted originally on January, 2007 CT scan as 3.6 mm for the one on the right (maybe the left, now I forget) side (which is now the biggest one). So it has been a year and a half almost that these nodules have been there and growing very slowly but not calcifying. The Pulomary guy says there is a possibility of Human Diroflaria Immitis (heartworms from dog), he asked if we had animals (which we do, and a year and a half ago, our dog was treated for heartworms but has since died from a car hitting him). My husband had a blood test to rule out the debillitating Arthritis which can cause these nodules (Rheumatoid), so I thought I would ask here to see if anyone had any insight. Thanks.