Aelurostrongylus abstrusus, popularly known as “feline pulmonary worm”, it is a nematode that affects the respiratory system of felines causing aelurostrongylosis. This parasite can be found in the host’s bronchi and pulmonary arteries. The clinical signs presented vary according to the animal’s immune response and severity of the infection, the host might present apathy, dyspnea, syncope, wheezing, sneezing, among others. This report aims to describe a case of aelurostrostrilylosis in a feline of wildlife threatened of extinction. The animal, Leopardus wiedii (Schinz, 1821), popularly known as Margay, was found in an urban perimeter in the municipality of Anchieta, state of Santa Catarina (SC) in Brazil and attended at the Veterinary Clinic CLINIVET, of the University of the West of Santa Catarina - UNOESC, campus of São Miguel do Oeste (SC). In the initial clinical evaluation, the patient presented with deambulatory difficulties, biological samples were collected for further investigation. In the coproparasitological exam, parasitism was diagnosed by A. abstrusus, however the animal did not present any clinical signs related to the respiratory system. The results of this report indicate that the species L. wiedii, diagnosed with subclinical infection, can act as a wild reservoir for A. abstrusus, serving as a source of infection for other species of wild felids and also for domestic ones. This highlights the importance of effective public policies for the conservation, management and study of diseases that affect wild cats, especially species that need more urgent attention, that is, those threatened of extinction.