Incidence and regional distribution of the lungworm Aelurostrongylus abstrusus in cats in Croatia

Lungworm Aelurostrongylus abstrusus is a cat's lung parasite with an indirect life cycle. Its predominant sites are terminal bronchioles and alveolar ducts. In the study, two populations of cats were examined. The first group consisted of feral cats (N=50) in the rural areas of the County of Zagorje (northwest Croatia), while the second group included cats from the urban area of the City of Zagreb. For the second group, data were collected from faecal examination (N=529) from the Department of Parasitology and the gross and histopathological findings of cats' lungs (N=128) at the Department of General Pathology and Pathological Morphology of the Faculty of Veterinary Medicine, Zagreb. In the first group, histopathological examination was carried out and the Ae. abstrusus was diagnosed in 22% (N=11); in the second group, Ae. abstrusus was diagnosed in 0.38% (N=2) of the faecal examinations in the eight year period (1990-1998) and 3.9% (N=5) on histopathological examination of cats' lungs, also in the same period. Histopathological examination showed alveoli, bronchiole, and alveolar ducts filled with eggs and larvae of Ae. abstrusus, disruption of alveolar septa, cellular infiltrate (mostly cosinophils, macrophages, lymphocytes and few multinucleated giant cells), peribronchial cell infiltration, and a striking hyperplasia and hypertrophy of smooth muscle, i.e. medial layer, of the pulmonic arteries.