Structural and ultrastructural changes in the lungs of cats Felis catus (Linnaeus, 1758) experimentally infected with D. immitis (Leidy, 1856)

Pulmonary artery dissection causing haemothorax in a cat: potential role of Dirofilaria immitis infection and literature review

“…Other lung alterations occurring less frequently and also detected in the present case include bronchitis/bronchiolitis, bronchi and bronchiole gland hyperplasia, bronchiolar smooth muscle hypertrophy, disorganization and vacuolization of muscle cells of the tunica media of pulmonary arteries, alveolar emphysema, and proliferation of smooth muscle cells in the pulmonary parenchyma [22].…”

“…Considering the absence of right ventricular hypertrophy in the cat of the present report, the hypothesis of pulmonary artery dissection consequent to pulmonary hypertension seems unlikely. Severe and chronic endo-mesoarteritis associated with medial degeneration observed in the cat of the present report, which was attributable to the mechanical action of the parasites [22], could be considered as the most reliable predisposing factor for the pulmonary artery dissection development. Indeed, degenerative processes of the tunica media (such as cystic medionecrosis or cystic medial degeneration) have been reported as underlying causes in both human [17] and canine [9] pulmonary artery dissection.…”

“…Gross and histopathological findings have been widely described in both experimentally [21,22] and naturally [23] heartworm-infected cats. As seen in the cat of the present case report, most commonly there are 1 to 4 adult heartworms per cat [23] with villous…”

“…University of Turin's Institutional Research Information System and Open Access Institutional Repository eosinophilic and lymphoplasmacytic endarteritis, intimal proliferation with fibrosis, and frequently observed pulmonary arterial medial hypertrophy and hyperplasia [21,22,23].…”

Temporal Pattern of Circulating Antigens and Antibody Responses in Cats Experimentally Infected with Dirofilaria immitis

“…Immature adult heartworms reaching the pulmonary arteries at approximately 2.5 -4.0 months post infection can cause significant lung pathology in infected cats, a condition referred to as heartworm-associated respiratory disease or HARD ). This stage is associated with an intense immune response, which results in the elimination of most of the immature worms and occurs regardless of whether adult worms are present or will develop at some future time (Dillon et al 2008, Lee et al 2010, Maia et al 2011.…”