Not everything is an important lesion: Anatomical structures, non-lesions, artifacts, lesions without clinical significance, and postmortem findings in domestic and feral pigs (Sus scrofa)

Abstract

The interpretation of the changes observed at necropsy is an important step for the success of the final diagnosis. This article aims to describe and illustrate the anatomical structures, non-lesions, artifacts, lesions without clinical significance and postmortem changes observed in domestic and wild pigs. Moreover, the article also recommends collection techniques of organs or structures for the diagnosis of diseases affecting this species. The main anatomical structures and non-lesions described are marginal lingual papillae, pars oesophagea of the stomach, torus pyloricus, and well demarcated lobular pattern of the liver (gastrointestinal system); tonsils of the soft palate, gastric lymphoid tissue, Peyer's patches of the small intestine, marginal folds of the spleen (hematopoietic system); prominent mediastinum testis and placental areolae (reproductive system); pulmonary atelectasis and periople (fetus); and carpal glands (integumentary system). The discussed artifacts related to euthanasia are petechiae on the surface of the lung and kidney, false anemia due to exsanguination, subdural hemorrhage due to cerebral concussion, pseudoinfarcts of the spleen, and cerebriform appearance of the small intestine. Lesions without clinical significance described are renal cysts, lymph nodes with iron pigment, papillomas and hemangiomas on the scrotum, osseous metaplasia in the mesentery, and hyperemia of the gastric mucosa. Commonly found postmortem changes are livor mortis, pale muscles, pseudomelanosis, and serosanguinous fluid in the thoracic and abdominal cavities of fetuses.