Gastrointestinal helminths and related histopathological lesions in black-necked swans Cygnus melancoryphus from the Carlos Anwandter Nature Sanctuary, Southern Chile

Abstract

Black-necked swans are distributed across South America and face conservation problems in Chile according to data of the State institution SAG. The aim of this study was to identify helminths and to assess associated tissue damage via histopathology. A total of 19,291 parasites were isolated from 21 examined birds; 17 species were identified, including nematodes, flukes, and tapeworms. Of these, 12 were new host records, 13 were reported for the first time in Chile, and 5 were new records for the Neotropical region. Further, the flukes Schistosomatidae gen. sp. and Echinostoma echinatum are of zoonotic concern. Regarding histopathology, an inflammatory response was found along the birds’ entire digestive tract. Nevertheless, it is difficult to declare that there is a clear association between such lesions and isolated parasites, as other noxa could be responsible as well. Although in some cases there was an evident association, such inflammatory responses and necrosis were minimal, as occurred with Capillaria, Retinometra, Catatropis, Echinostoma, and Schistosomatidae gen. sp. Nevertheless, Epomidiostomum vogelsangi caused granulomatous injuries, an important inflammatory response, and necrosis, but it always circumscribed to superficial layers of the gizzard. Conversely, Paramonostomum was not associated with an inflammatory response despite a high parasitic load.

Gastrointestinal helminths of waterfowl (Anatidae: Anatinae) in the Lerma marshes of central Mexico: Some pathological aspects

“…in the small intestine. Previous studies also mention the development of granulomas with E. uncinata inside ( Work et al, 2004 ); Da Silveira et al, 2006 ; Oyarzún et al (2019) and Graczyk et al (1993) associated them with N. attenuatus . Work et al (2004) also pointed out that E. uncinatum caused dilation of the glands with flat epithelium, overproduction of mucus, ulcers and sporadically the formation of granulomas.…”

“… Behm and Ovington (2000) pointed out that the presence of eosinophils is related to the destruction of large foreign bodies to be phagocytosed, as well as participating in tissue repair by fibrosis and releasing antigens; however, these cells did not appear in the rest of the infections, possibly due to the time of infection or because several of these species migrate to other organs during their development. Other species of cestodes, e.g., Retinometra bulbocirrosus , have been collected in the same organs ( Oyarzún et al, 2019 ); however, authors do not report lesions in these parts of the digestive tract. Additionally, in our study, this cestode species along F. fasciolaris, Diorchis sp., and the acanthocephalans P. constrictum and Filicollis sp., caused systemic necrosis at the implantation site.…”

Динаміка Живої Маси Гусенят За Амідостомозу В Гусей

“…Очевидним є те, що гельмінтози поширені серед різних видів тварин та клінічно не завжди можуть бути діагностованими, оскільки перебіг хвороби може бути латентним. Незважаючи на те, що впродовж усього життя птиця заражається значною кількістю паразитів, залишаються ще недостатньо вивчені біологічні та патологічні аспекти, що є наслідками паразитизму [3,4].…”

Morphological parameters of geese blood in amidostomy invasion

“…Окрім того паразити порушують процес травлення та транзит кишкового вмісту (Padilla-Aguilar et al, 2020). Паразитування статевозрілих нематод спричиняє ушкодження, десквамацію епітелію ворсинок, некробіотичні процеси в поверхневих шарах слизової оболонки кишки та гіперплазію лімфатичної тканини (Panikar et al, 2016;Oyarzún-Ruiz et al, 2019).…”