Ascaridia hermaphrodita (Froelich, 1789) and Ascaridia columbae (Gmelin, 1780) in neotropical psittacine birds.

Gastrointestinal parasites found in four Neotropical psittacine birds of the species Ara macao, Amazona aestiva, Amazona vinacea and Pionus maximiliani have been reported. The carcasses of the animals were received from commercial breeders and a rehabilitation center for necropsy. In total, 589 parasites were collected during the exams and submitted for morphological analysis and taxonomic identification. Twenty parasites from each host were cleaned with lactophenol and analyzed by light microscopy, while four parasites from each host were prepared for scanning electron microscopy. Tissue samples were forwarded for histological analysis in search of erratic larvae; however, none were found. Parasites from A. macao, A. aestiva and A. vinacea were identified as Ascaridia hermaphrodita, whereas parasites from P. maximiliani were identified as Ascaridia columbae, promoting the first report of A. columbae in P. maximiliani. All birds were kept in enclosures with access to the ground, facilitating parasitism. Pionus maximiliani and A. vinacea were kept together in the same enclosure with high population density. Additionally, synanthropic animals, such as Columbiformes, were observed in the same enclosure, facilitating infection with A. columbae. The identification of Ascaridia species that parasitizes psittacine birds helps to improve prevention and control measures, thus enhancing avian health and welfare.