Identification of Macracanthorhynchus hirudinaceus, Stephanurus dentatus and Trichuris suis in Native Pigs on Marajó Island
Technification of pig farming in recent decades has led to a significant reduction in the occurrence of helminth parasitism. However, the production of pigs in free-range systems is still a common reality in rural areas of Brazil, such as Marajó Island, in the State of Pará, a Brazilian Amazonian biome. Therefore, the present work describes the main parasitological and anatomopathological findings of six pigs in a sample of 23, of different age groups, raised under free-range conditions on native pastures on Marajó Island. During slaughter, the presence of Stephanurus dentatus in the ureters and renal pelvis, Macracanthorhynchus hirudinaceus in the small intestine and Trichuris suis in the cecum and colon was detected in these six pigs. The histopathology results showed different types of lesions, including mild granulomatous infiltrates in the lymph nodes, granulomatous inflammation and brown pigment in the tonsils, hyperkeratosis in the esophagus and nonglandular stomach, lung with dark pigment in the bronchioles and intra-alveolar macrophages, as well as squamous metaplasia of the peribronchial glands, hemosiderosis in the spleen, liver with marked extramedullary hematopoiesis, mild hepatitis and abscess caused by parasitic migration with eosinophils, intestinal edema and neuronal lipofuscinosis in the spinal cord. From these findings, it can be inferred that free-range pigs on Marajó Island are susceptible to helminths, reflecting the high degree of environmental contamination in which these animals are reared, and that such ecosystems can function as reservoirs of these agents. Helminth infections lead to losses in pig farming in the Amazon biome, showing the importance of the strategic control of these parasites.